diff --git a/.travis.yml b/.travis.yml
index d8bc595d79..36e10e1a91 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,20 +14,28 @@ env:
     - LLVM_VERSION="3.8" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
     - LLVM_VERSION="3.8" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
     - LLVM_VERSION="3.8" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="3.8" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE=
+    - LLVM_VERSION="3.8" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE="--release"
     - LLVM_VERSION="3.9" BINDGEN_JOB="test"         BINDGEN_PROFILE=
     - LLVM_VERSION="3.9" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
     - LLVM_VERSION="3.9" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
     - LLVM_VERSION="3.9" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="3.9" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE=
+    - LLVM_VERSION="3.9" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE="--release"
     - LLVM_VERSION="4.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
     - LLVM_VERSION="4.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
     - LLVM_VERSION="4.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
     - LLVM_VERSION="4.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="4.0" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE=
+    - LLVM_VERSION="4.0" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE="--release"
     - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=
     - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release"
     - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE=            BINDGEN_FEATURES="testing_only_extra_assertions"
     - LLVM_VERSION="5.0" BINDGEN_JOB="test"         BINDGEN_PROFILE="--release" BINDGEN_FEATURES="testing_only_extra_assertions"
     - LLVM_VERSION="5.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE=
     - LLVM_VERSION="5.0" BINDGEN_JOB="integration"  BINDGEN_PROFILE="--release"
+    - LLVM_VERSION="5.0" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE=
+    - LLVM_VERSION="5.0" BINDGEN_JOB="nofeatures"   BINDGEN_PROFILE="--release"
     - LLVM_VERSION="5.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE=
     - LLVM_VERSION="5.0" BINDGEN_JOB="expectations" BINDGEN_PROFILE="--release"
     - LLVM_VERSION="5.0" BINDGEN_JOB="misc"
diff --git a/Cargo.toml b/Cargo.toml
index 2f98a0ea99..232d9c3596 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -54,7 +54,7 @@ lazy_static = "1"
 peeking_take_while = "0.1.2"
 quote = { version = "1", default-features = false }
 regex = "1.0"
-which = ">=1.0, <3.0"
+which = { version = ">=1.0, <3.0", optional = true }
 shlex = "0.1"
 fxhash = "0.2"
 # New validation in 0.3.6 breaks bindgen-integration:
@@ -70,9 +70,11 @@ optional = true
 version = "0.4"
 
 [features]
-default = ["logging", "clap"]
+default = ["logging", "clap", "which-rustfmt"]
 logging = ["env_logger", "log"]
 static = []
+# Dynamically discover a `rustfmt` binary using the `which` crate
+which-rustfmt = ["which"]
 
 # These features only exist for CI testing -- don't use them if you're not hacking
 # on bindgen!
diff --git a/ci/script.sh b/ci/script.sh
index 880896cd72..7003618a56 100755
--- a/ci/script.sh
+++ b/ci/script.sh
@@ -14,19 +14,31 @@ case "$BINDGEN_JOB" in
         # Need rustfmt to compare the test expectations.
         rustup update nightly
         rustup component add rustfmt
-	export RUSTFMT="$(rustup which rustfmt)"
-        cargo test $BINDGEN_PROFILE --features "$BINDGEN_FEATURES"
+        rustup component add --toolchain nightly rustfmt
+        RUSTFMT="$(rustup which rustfmt)"
+        export RUSTFMT
+        cargo test "$BINDGEN_PROFILE" --features "$BINDGEN_FEATURES"
         ./ci/assert-no-diff.sh
         ;;
 
     "integration")
         cd ./bindgen-integration
-        cargo test $BINDGEN_PROFILE --features "$BINDGEN_FEATURES"
+        cargo test "$BINDGEN_PROFILE" --features "$BINDGEN_FEATURES"
+        ;;
+
+    "nofeatures")
+        rustup update nightly
+        rustup component add rustfmt
+        rustup component add --toolchain nightly rustfmt
+        RUSTFMT="$(rustup which rustfmt)"
+        export RUSTFMT
+        cargo test "$BINDGEN_PROFILE" --no-default-features
+        ./ci/assert-no-diff.sh
         ;;
 
     "expectations")
         cd ./tests/expectations
-        cargo test $BINDGEN_PROFILE
+        cargo test "$BINDGEN_PROFILE"
         ;;
 
     "misc")
@@ -43,6 +55,7 @@ case "$BINDGEN_JOB" in
         # TODO: Actually run quickchecks once `bindgen` is reliable enough.
         cargo test
         ;;
+
     *)
         echo "Error! Unknown \$BINDGEN_JOB: '$BINDGEN_JOB'"
         exit 1
diff --git a/src/lib.rs b/src/lib.rs
index b59c9271c7..722e53e9e5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,6 +32,7 @@ extern crate quote;
 extern crate proc_macro2;
 extern crate regex;
 extern crate shlex;
+#[cfg(feature = "which-rustfmt")]
 extern crate which;
 
 #[cfg(feature = "logging")]
@@ -1908,10 +1909,13 @@ impl Bindings {
         if let Ok(rustfmt) = env::var("RUSTFMT") {
             return Ok(Cow::Owned(rustfmt.into()));
         }
+        #[cfg(feature = "which-rustfmt")]
         match which::which("rustfmt") {
             Ok(p) => Ok(Cow::Owned(p)),
             Err(e) => Err(io::Error::new(io::ErrorKind::Other, format!("{}", e))),
         }
+        #[cfg(not(feature = "which-rustfmt"))]
+        Err(io::Error::new(io::ErrorKind::Other, "which wasn't enabled, and no rustfmt binary specified"))
     }
 
     /// Checks if rustfmt_bindings is set and runs rustfmt on the string