diff --git a/.github/workflows/continuous-integration-workflow.yaml b/.github/workflows/continuous-integration-workflow.yaml
index 3ba00ac0b..0b8fcca13 100644
--- a/.github/workflows/continuous-integration-workflow.yaml
+++ b/.github/workflows/continuous-integration-workflow.yaml
@@ -8,6 +8,8 @@ jobs:
     steps:
       - name: checkout
         uses: actions/checkout@v2
+        with:
+          submodules: recursive
       - name: install toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -24,7 +26,10 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - name: checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: recursive
       - name: install toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -54,6 +59,8 @@ jobs:
     steps:
       - name: checkout
         uses: actions/checkout@v2
+        with:
+          submodules: recursive
       - name: install toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -78,6 +85,8 @@ jobs:
     steps:
       - name: checkout
         uses: actions/checkout@v2
+        with:
+          submodules: recursive
       - name: install toolchain
         uses: actions-rs/toolchain@v1
         with:
@@ -109,3 +118,20 @@ jobs:
         with:
           command: check
           args: --manifest-path prost-build/Cargo.toml
+
+  vendored:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - name: install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+            toolchain: stable
+            default: true
+            profile: minimal
+      - name: cargo check
+        run: cd test-vendored && cargo check
+
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..6251abeb8
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "prost-build/third-party/protobuf"]
+	path = prost-build/third-party/protobuf
+	url = git@github.com:protocolbuffers/protobuf
diff --git a/Cargo.toml b/Cargo.toml
index a1225ae6b..534046007 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,6 +33,7 @@ exclude = [
   "fuzz",
   # Same counts for the afl fuzz targets
   "afl",
+  "test-vendored"
 ]
 
 [lib]
diff --git a/README.md b/README.md
index 4d526af29..242092c43 100644
--- a/README.md
+++ b/README.md
@@ -47,6 +47,13 @@ start-to-finish example.
 `proto3` syntax. `prost`'s goal is to make the generated code as simple as
 possible.
 
+### `protoc`
+
+It's recommended to install `protoc` locally in your path to improve build times.
+Prost uses `protoc` to parse protobuf files and will attempt to compile protobuf
+from source requiring a C++ toolchain. For more info checkout the [`prost-build`](prost-build)
+docs.
+
 ### Packages
 
 Prost can now generate code for `.proto` files that don't have a package spec. 
diff --git a/prost-build/Cargo.toml b/prost-build/Cargo.toml
index c50d487c1..e7415c8b2 100644
--- a/prost-build/Cargo.toml
+++ b/prost-build/Cargo.toml
@@ -12,6 +12,10 @@ readme = "README.md"
 description = "A Protocol Buffers implementation for the Rust Language."
 edition = "2018"
 
+[features]
+default = []
+vendored = []
+
 [dependencies]
 bytes = { version = "1", default-features = false }
 heck = "0.4"
@@ -27,6 +31,8 @@ regex = { version = "1.5.5", default-features = false, features = ["std", "unico
 
 [build-dependencies]
 which = { version = "4", default-features = false }
+cfg-if = "1"
+cmake = "0.1"
 
 [dev-dependencies]
 env_logger = { version = "0.8", default-features = false }
diff --git a/prost-build/README.md b/prost-build/README.md
index e16957c8e..248e0ffdf 100644
--- a/prost-build/README.md
+++ b/prost-build/README.md
@@ -7,6 +7,28 @@
 a Cargo build. See the crate [documentation](https://docs.rs/prost-build/) for examples
 of how to integrate `prost-build` into a Cargo project.
 
+## `protoc`
+
+`prost-build` uses `protoc` to parse the proto files. There are a few ways to make `protoc`
+available for `prost-build`. 
+
+The first option is to include `protoc` in your `PATH` this
+can be done by following the [`protoc` install instructions]. In addition, its possible to
+pass the `PROTOC=<my/path/to/protoc>` environment variable.
+
+[`protoc` install instructions]: https://github.com/protocolbuffers/protobuf#protocol-compiler-installation
+
+The second option is to provide the `vendored` feature flag to `prost-build`. This will
+force `prost-build` to compile `protoc` from the bundled source. This will require that
+you have the correct dependencies installed include a C++ toolchain, cmake, etc. For
+more info on what the required dependencies are check [here].
+
+[here]: https://github.com/protocolbuffers/protobuf/blob/master/src/README.md
+
+If you would like to always ignore vendoring `protoc` you can additionally pass
+`PROTOC_NO_VENDOR` and this will always check the `PATH`/`PROTOC` environment
+variables and never compile `protoc` from source.
+
 ## License
 
 `prost-build` is distributed under the terms of the Apache License (Version 2.0).
diff --git a/prost-build/build.rs b/prost-build/build.rs
index 7f5860f30..89abf0176 100644
--- a/prost-build/build.rs
+++ b/prost-build/build.rs
@@ -1,72 +1,29 @@
 //! Finds the appropriate `protoc` binary and Protobuf include directory for this host, and outputs
 //! build directives so that the main `prost-build` crate can use them.
 //!
-//! The following locations are checked for `protoc` in decreasing priority:
+//! This build script attempts to find `protoc` in a few ways:
 //!
-//!     1. The `PROTOC` environment variable.
-//!     2. The bundled `protoc`.
-//!     3. The `protoc` on the `PATH`.
-//!
-//! If no `protoc` binary is available in these locations, the build fails.
+//!     1. If `PROTOC_NO_VENDOR` is enabled, it will check the `PROTOC` environment variable
+//!         then check the `PATH` for a `protoc` or `protoc.exe`.
+//!     2. If the `vendored` feature flag is enabled or `protoc` can't be found via the environment
+//!         variable or in the `PATH` then `prost-build` will attempt to build `protoc` from the
+//!         bundled source code.
+//!     3. Otherwise, it will attempt to execute from the `PATH` and fail if it does not exist.
 //!
 //! The following locations are checked for the Protobuf include directory in decreasing priority:
 //!
 //!     1. The `PROTOC_INCLUDE` environment variable.
 //!     2. The bundled Protobuf include directory.
+//!
 
+use cfg_if::cfg_if;
 use std::env;
 use std::path::PathBuf;
+use which::which;
 
 /// Returns the path to the location of the bundled Protobuf artifacts.
 fn bundle_path() -> PathBuf {
-    env::current_dir()
-        .unwrap()
-        .join("third-party")
-        .join("protobuf")
-}
-
-/// Returns the path to the `protoc` pointed to by the `PROTOC` environment variable, if it is set.
-fn env_protoc() -> Option<PathBuf> {
-    let protoc = match env::var_os("PROTOC") {
-        Some(path) => PathBuf::from(path),
-        None => return None,
-    };
-
-    Some(protoc)
-}
-
-/// We can only use a bundled protoc if the interpreter necessary to load the binary is available.
-///
-/// The interpreter is specific to the binary and can be queried via e.g. `patchelf
-/// --print-interpreter`, or via readelf, or similar.
-fn is_interpreter(path: &'static str) -> bool {
-    // Here we'd check for it being executable and other things, but for now it being present is
-    // probably good enough.
-    std::fs::metadata(path).is_ok()
-}
-
-/// Returns the path to the bundled `protoc`, if it is available for the host platform.
-fn bundled_protoc() -> Option<PathBuf> {
-    let protoc_bin_name = match (env::consts::OS, env::consts::ARCH) {
-        ("linux", "x86") if is_interpreter("/lib/ld-linux.so.2") => "protoc-linux-x86_32",
-        ("linux", "x86_64") if is_interpreter("/lib64/ld-linux-x86-64.so.2") => {
-            "protoc-linux-x86_64"
-        }
-        ("linux", "aarch64") if is_interpreter("/lib/ld-linux-aarch64.so.1") => {
-            "protoc-linux-aarch_64"
-        }
-        ("macos", "x86_64") => "protoc-osx-x86_64",
-        ("macos", "aarch64") => "protoc-osx-aarch64",
-        ("windows", _) => "protoc-win32.exe",
-        _ => return None,
-    };
-
-    Some(bundle_path().join(protoc_bin_name))
-}
-
-/// Returns the path to the `protoc` included on the `PATH`, if it exists.
-fn path_protoc() -> Option<PathBuf> {
-    which::which("protoc").ok()
+    env::current_dir().unwrap().join("third-party")
 }
 
 /// Returns the path to the Protobuf include directory pointed to by the `PROTOC_INCLUDE`
@@ -98,14 +55,56 @@ fn bundled_protoc_include() -> PathBuf {
     bundle_path().join("include")
 }
 
+/// Check for `protoc` via the `PROTOC` env var or in the `PATH`.
+fn path_protoc() -> Option<PathBuf> {
+    env::var_os("PROTOC")
+        .map(PathBuf::from)
+        .or_else(|| which("protoc").ok())
+}
+
+/// Returns true if the vendored flag is enabled.
+fn vendored() -> bool {
+    cfg_if! {
+        if #[cfg(feature = "vendored")] {
+            true
+        } else {
+            false
+        }
+    }
+}
+
+/// Compile `protoc` via `cmake`.
+fn compile() -> Option<PathBuf> {
+    let protobuf_src = bundle_path().join("protobuf").join("cmake");
+
+    println!("cargo:rerun-if-changed={}", protobuf_src.display());
+
+    let dst = cmake::Config::new(protobuf_src).build();
+
+    Some(dst.join("bin").join("protoc"))
+}
+
+/// Try to find a `protoc` through a few methods.
+///
+/// Check module docs for more info.
+fn protoc() -> Option<PathBuf> {
+    if env::var_os("PROTOC_NO_VENDOR").is_some() {
+        path_protoc()
+    } else if vendored() {
+        compile()
+    } else {
+        path_protoc().or_else(compile)
+    }
+}
+
 fn main() {
-    let protoc = env_protoc()
-        .or_else(bundled_protoc)
-        .or_else(path_protoc)
-        .expect(
-            "Failed to find the protoc binary. The PROTOC environment variable is not set, \
-             there is no bundled protoc for this platform, and protoc is not in the PATH",
-        );
+    let protoc = protoc().expect(
+        "Failed to find or build the protoc binary. The PROTOC environment \
+    is not set, `protoc` is not in PATH or you are missing the requirements to compile protobuf \
+    from source. \n \
+    Check out the `prost-build` README for instructions on the requirements: \
+    https://github.com/tokio-rs/prost#generated-code",
+    );
 
     let protoc_include = env_protoc_include().unwrap_or_else(bundled_protoc_include);
 
diff --git a/prost-build/src/lib.rs b/prost-build/src/lib.rs
index 5259ea4dd..1ba6f7e0a 100644
--- a/prost-build/src/lib.rs
+++ b/prost-build/src/lib.rs
@@ -97,17 +97,28 @@
 //! PROTOC_INCLUDE=/usr/include
 //! ```
 //!
-//! If `PROTOC` is not found in the environment, then a pre-compiled `protoc` binary bundled in the
-//! prost-build crate is used. Pre-compiled `protoc` binaries exist for Linux (non-musl), macOS,
-//! and Windows systems. If no pre-compiled `protoc` is available for the host platform, then the
-//! `protoc` or `protoc.exe` binary on the `PATH` is used. If `protoc` is not available in any of
-//! these fallback locations, then the build fails.
+//! If no `PROTOC` environment variable is set then `prost-build` will search the
+//! current path for `protoc` or `protoc.exe`. If `protoc` is not found via these
+//! two methods then `prost-build` will attempt to compile `protoc` from the bundled
+//! source.
+//!
+//! If you would not like `prost-build` to not compile `protoc` from source ever then
+//! ensure you have set `PROTO_NO_VENDOR` environment variable as this will disable
+//! compiling from source even if the `vendored` feature flag is enabled.
+//!
+//! If you would like to always compile from source then setting the `vendored` feature
+//! flag will force `prost-build` to always build `protoc` from source.
 //!
 //! If `PROTOC_INCLUDE` is not found in the environment, then the Protobuf include directory
 //! bundled in the prost-build crate is be used.
 //!
-//! To force `prost-build` to use the `protoc` on the `PATH`, add `PROTOC=protoc` to the
-//! environment.
+//! ### Compiling `protoc` from source
+//!
+//! Compiling `protoc` from source requires a few external dependencies. Currently,
+//! `prost-build` uses `cmake` to build `protoc`. For more information check out the
+//! [protobuf build instructions](protobuf-build).
+//!
+//! [protobuf-build]: https://github.com/protocolbuffers/protobuf/blob/master/src/README.md
 
 mod ast;
 mod code_generator;
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/any.proto b/prost-build/third-party/include/google/protobuf/any.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/any.proto
rename to prost-build/third-party/include/google/protobuf/any.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/api.proto b/prost-build/third-party/include/google/protobuf/api.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/api.proto
rename to prost-build/third-party/include/google/protobuf/api.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/compiler/plugin.proto b/prost-build/third-party/include/google/protobuf/compiler/plugin.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/compiler/plugin.proto
rename to prost-build/third-party/include/google/protobuf/compiler/plugin.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/descriptor.proto b/prost-build/third-party/include/google/protobuf/descriptor.proto
similarity index 98%
rename from prost-build/third-party/protobuf/include/google/protobuf/descriptor.proto
rename to prost-build/third-party/include/google/protobuf/descriptor.proto
index 9f0ce6cde..156e410ae 100644
--- a/prost-build/third-party/protobuf/include/google/protobuf/descriptor.proto
+++ b/prost-build/third-party/include/google/protobuf/descriptor.proto
@@ -348,17 +348,17 @@ message FileOptions {
   optional string java_package = 1;
 
 
-  // If set, all the classes from the .proto file are wrapped in a single
-  // outer class with the given name.  This applies to both Proto1
-  // (equivalent to the old "--one_java_file" option) and Proto2 (where
-  // a .proto always translates to a single class, but you may want to
-  // explicitly choose the class name).
+  // Controls the name of the wrapper Java class generated for the .proto file.
+  // That class will always contain the .proto file's getDescriptor() method as
+  // well as any top-level extensions defined in the .proto file.
+  // If java_multiple_files is disabled, then all the other classes from the
+  // .proto file will be nested inside the single wrapper outer class.
   optional string java_outer_classname = 8;
 
-  // If set true, then the Java code generator will generate a separate .java
+  // If enabled, then the Java code generator will generate a separate .java
   // file for each top-level message, enum, and service defined in the .proto
-  // file.  Thus, these types will *not* be nested inside the outer class
-  // named by java_outer_classname.  However, the outer class will still be
+  // file.  Thus, these types will *not* be nested inside the wrapper class
+  // named by java_outer_classname.  However, the wrapper class will still be
   // generated to contain the file's getDescriptor() method as well as any
   // top-level extensions defined in the file.
   optional bool java_multiple_files = 10 [default = false];
@@ -496,6 +496,8 @@ message MessageOptions {
   // this is a formalization for deprecating messages.
   optional bool deprecated = 3 [default = false];
 
+  reserved 4, 5, 6;
+
   // Whether the message is an automatically generated map entry type for the
   // maps field.
   //
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/duration.proto b/prost-build/third-party/include/google/protobuf/duration.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/duration.proto
rename to prost-build/third-party/include/google/protobuf/duration.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/empty.proto b/prost-build/third-party/include/google/protobuf/empty.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/empty.proto
rename to prost-build/third-party/include/google/protobuf/empty.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/field_mask.proto b/prost-build/third-party/include/google/protobuf/field_mask.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/field_mask.proto
rename to prost-build/third-party/include/google/protobuf/field_mask.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/source_context.proto b/prost-build/third-party/include/google/protobuf/source_context.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/source_context.proto
rename to prost-build/third-party/include/google/protobuf/source_context.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/struct.proto b/prost-build/third-party/include/google/protobuf/struct.proto
similarity index 98%
rename from prost-build/third-party/protobuf/include/google/protobuf/struct.proto
rename to prost-build/third-party/include/google/protobuf/struct.proto
index 545215c25..0ac843ca0 100644
--- a/prost-build/third-party/protobuf/include/google/protobuf/struct.proto
+++ b/prost-build/third-party/include/google/protobuf/struct.proto
@@ -55,8 +55,8 @@ message Struct {
 
 // `Value` represents a dynamically typed value which can be either
 // null, a number, a string, a boolean, a recursive struct value, or a
-// list of values. A producer of value is expected to set one of that
-// variants, absence of any variant indicates an error.
+// list of values. A producer of value is expected to set one of these
+// variants. Absence of any variant indicates an error.
 //
 // The JSON representation for `Value` is JSON value.
 message Value {
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/timestamp.proto b/prost-build/third-party/include/google/protobuf/timestamp.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/timestamp.proto
rename to prost-build/third-party/include/google/protobuf/timestamp.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/type.proto b/prost-build/third-party/include/google/protobuf/type.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/type.proto
rename to prost-build/third-party/include/google/protobuf/type.proto
diff --git a/prost-build/third-party/protobuf/include/google/protobuf/wrappers.proto b/prost-build/third-party/include/google/protobuf/wrappers.proto
similarity index 100%
rename from prost-build/third-party/protobuf/include/google/protobuf/wrappers.proto
rename to prost-build/third-party/include/google/protobuf/wrappers.proto
diff --git a/prost-build/third-party/protobuf b/prost-build/third-party/protobuf
new file mode 160000
index 000000000..22d0e265d
--- /dev/null
+++ b/prost-build/third-party/protobuf
@@ -0,0 +1 @@
+Subproject commit 22d0e265de7d2b3d2e9a00d071313502e7d4cccf
diff --git a/prost-build/third-party/protobuf/LICENSE b/prost-build/third-party/protobuf/LICENSE
deleted file mode 100644
index 19b305b00..000000000
--- a/prost-build/third-party/protobuf/LICENSE
+++ /dev/null
@@ -1,32 +0,0 @@
-Copyright 2008 Google Inc.  All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-    * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-    * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-Code generated by the Protocol Buffer compiler is owned by the owner
-of the input file used when generating it.  This code is not
-standalone and requires a support library to be linked with it.  This
-support library is itself covered by the above license.
diff --git a/prost-build/third-party/protobuf/protoc-linux-aarch_64 b/prost-build/third-party/protobuf/protoc-linux-aarch_64
deleted file mode 100755
index 10e33fcfc..000000000
Binary files a/prost-build/third-party/protobuf/protoc-linux-aarch_64 and /dev/null differ
diff --git a/prost-build/third-party/protobuf/protoc-linux-x86_32 b/prost-build/third-party/protobuf/protoc-linux-x86_32
deleted file mode 100755
index 0f2b633ef..000000000
Binary files a/prost-build/third-party/protobuf/protoc-linux-x86_32 and /dev/null differ
diff --git a/prost-build/third-party/protobuf/protoc-linux-x86_64 b/prost-build/third-party/protobuf/protoc-linux-x86_64
deleted file mode 100755
index e4385d14b..000000000
Binary files a/prost-build/third-party/protobuf/protoc-linux-x86_64 and /dev/null differ
diff --git a/prost-build/third-party/protobuf/protoc-osx-aarch64 b/prost-build/third-party/protobuf/protoc-osx-aarch64
deleted file mode 100755
index e2ba14d7e..000000000
Binary files a/prost-build/third-party/protobuf/protoc-osx-aarch64 and /dev/null differ
diff --git a/prost-build/third-party/protobuf/protoc-osx-x86_64 b/prost-build/third-party/protobuf/protoc-osx-x86_64
deleted file mode 100755
index aacc92892..000000000
Binary files a/prost-build/third-party/protobuf/protoc-osx-x86_64 and /dev/null differ
diff --git a/prost-build/third-party/protobuf/protoc-win32.exe b/prost-build/third-party/protobuf/protoc-win32.exe
deleted file mode 100755
index 9398c1668..000000000
Binary files a/prost-build/third-party/protobuf/protoc-win32.exe and /dev/null differ
diff --git a/prost-build/third-party/update-bundled-protobuf.sh b/prost-build/third-party/update-bundled-protobuf.sh
deleted file mode 100755
index 05655372c..000000000
--- a/prost-build/third-party/update-bundled-protobuf.sh
+++ /dev/null
@@ -1,50 +0,0 @@
-#!/bin/bash
-
-set -ex
-
-if [ "$#" -ne 1 ]
-then
-  echo "Usage: $0 <protobuf-version>"
-  exit 1
-fi
-
-DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
-VERSION="$1"
-TEMPDIR=$(mktemp -d "protobuf-$VERSION-XXX")
-ARCHS=( \
-  "linux-aarch_64" \
-  "linux-x86_32" \
-  "linux-x86_64" \
-  "osx-x86_64" \
-  "win32" \
-)
-
-for ARCH in "${ARCHS[@]}"; do
-  mkdir "$TEMPDIR/$ARCH"
-  curl --proto '=https' --tlsv1.2 -sSfL \
-    "https://github.com/protocolbuffers/protobuf/releases/download/v$VERSION/protoc-$VERSION-$ARCH.zip" \
-    -o "$TEMPDIR/$ARCH/protoc.zip"
-
-  EXTENSION=""
-  if [[ "$ARCH" == *"win"* ]]; then
-    EXTENSION=".exe"
-  fi
-
-  unzip "$TEMPDIR/$ARCH/protoc.zip" -d "$TEMPDIR/$ARCH"
-  mv "$TEMPDIR/$ARCH/bin/protoc$EXTENSION" "$DIR/protobuf/protoc-$ARCH$EXTENSION"
-done
-
-
-# Update the include directory
-rm -rf "$DIR/protobuf/include"
-mv "$TEMPDIR/linux-x86_64/include" "$DIR/protobuf/"
-
-# Update the Protocol Buffers license.
-mkdir "$TEMPDIR/src"
-curl --proto '=https' --tlsv1.2 -sSfL \
-  "https://github.com/protocolbuffers/protobuf/archive/v$VERSION.zip" \
-  -o "$TEMPDIR/src/protobuf.zip"
-unzip "$TEMPDIR/src/protobuf.zip" -d "$TEMPDIR/src"
-mv "$TEMPDIR/src/protobuf-$VERSION/LICENSE" "$DIR/protobuf/LICENSE"
-
-rm -rf $TEMPDIR
diff --git a/prost-build/third-party/update-vendored-protobuf.sh b/prost-build/third-party/update-vendored-protobuf.sh
new file mode 100755
index 000000000..d8d741ad5
--- /dev/null
+++ b/prost-build/third-party/update-vendored-protobuf.sh
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -ex
+
+if [ "$#" -ne 1 ]
+then
+  echo "Usage: $0 <protobuf-version>"
+  exit 1
+fi
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"
+VERSION="$1"
+TEMPDIR=$(mktemp -d "protobuf-$VERSION-XXX")
+ARCH="linux-x86_64"
+
+mkdir "$TEMPDIR/$ARCH"
+curl --proto '=https' --tlsv1.2 -sSfL \
+  "https://github.com/protocolbuffers/protobuf/releases/download/v$VERSION/protoc-$VERSION-$ARCH.zip" \
+  -o "$TEMPDIR/$ARCH/protoc.zip"
+
+unzip "$TEMPDIR/$ARCH/protoc.zip" -d "$TEMPDIR/$ARCH"
+
+# Update the include directory
+rm -rf "$DIR/include"
+mv "$TEMPDIR/linux-x86_64/include" "$DIR/include/"
+
+
+rm -rf $TEMPDIR
+cd "$DIR/protobuf"
+git checkout "v$VERSION"
+cd $DIR
+
+echo "third-party protobuf items updated to v$VERSION"
\ No newline at end of file
diff --git a/prost-types/src/protobuf.rs b/prost-types/src/protobuf.rs
index 1440b4c00..25e82179b 100644
--- a/prost-types/src/protobuf.rs
+++ b/prost-types/src/protobuf.rs
@@ -343,17 +343,17 @@ pub struct FileOptions {
     /// domain names.
     #[prost(string, optional, tag="1")]
     pub java_package: ::core::option::Option<::prost::alloc::string::String>,
-    /// If set, all the classes from the .proto file are wrapped in a single
-    /// outer class with the given name.  This applies to both Proto1
-    /// (equivalent to the old "--one_java_file" option) and Proto2 (where
-    /// a .proto always translates to a single class, but you may want to
-    /// explicitly choose the class name).
+    /// Controls the name of the wrapper Java class generated for the .proto file.
+    /// That class will always contain the .proto file's getDescriptor() method as
+    /// well as any top-level extensions defined in the .proto file.
+    /// If java_multiple_files is disabled, then all the other classes from the
+    /// .proto file will be nested inside the single wrapper outer class.
     #[prost(string, optional, tag="8")]
     pub java_outer_classname: ::core::option::Option<::prost::alloc::string::String>,
-    /// If set true, then the Java code generator will generate a separate .java
+    /// If enabled, then the Java code generator will generate a separate .java
     /// file for each top-level message, enum, and service defined in the .proto
-    /// file.  Thus, these types will *not* be nested inside the outer class
-    /// named by java_outer_classname.  However, the outer class will still be
+    /// file.  Thus, these types will *not* be nested inside the wrapper class
+    /// named by java_outer_classname.  However, the wrapper class will still be
     /// generated to contain the file's getDescriptor() method as well as any
     /// top-level extensions defined in the file.
     #[prost(bool, optional, tag="10", default="false")]
@@ -1681,8 +1681,8 @@ pub struct Struct {
 }
 /// `Value` represents a dynamically typed value which can be either
 /// null, a number, a string, a boolean, a recursive struct value, or a
-/// list of values. A producer of value is expected to set one of that
-/// variants, absence of any variant indicates an error.
+/// list of values. A producer of value is expected to set one of these
+/// variants. Absence of any variant indicates an error.
 ///
 /// The JSON representation for `Value` is JSON value.
 #[derive(Clone, PartialEq, ::prost::Message)]
diff --git a/test-vendored/Cargo.toml b/test-vendored/Cargo.toml
new file mode 100644
index 000000000..0613874f4
--- /dev/null
+++ b/test-vendored/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "test-vendored"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+[build-dependencies]
+prost-build = { path = "../prost-build", features = ["vendored"] }
diff --git a/test-vendored/build.rs b/test-vendored/build.rs
new file mode 100644
index 000000000..ada1dc4b2
--- /dev/null
+++ b/test-vendored/build.rs
@@ -0,0 +1,3 @@
+fn main() {
+    prost_build::compile_protos(&["proto/foo.proto"], &["proto"]).unwrap()
+}
diff --git a/test-vendored/proto/foo.proto b/test-vendored/proto/foo.proto
new file mode 100644
index 000000000..40160936b
--- /dev/null
+++ b/test-vendored/proto/foo.proto
@@ -0,0 +1,6 @@
+syntax = "proto3";
+package foo;
+
+message Foo {
+    string bar = 1;
+}
\ No newline at end of file
diff --git a/test-vendored/src/lib.rs b/test-vendored/src/lib.rs
new file mode 100644
index 000000000..8b1378917
--- /dev/null
+++ b/test-vendored/src/lib.rs
@@ -0,0 +1 @@
+