diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1c59d83fe5..dda5338bb9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -174,6 +174,7 @@ jobs:
           - i686-pc-windows-msvc
           - i686-unknown-linux-gnu
           - i686-unknown-linux-musl
+          - mipsel-unknown-linux-gnu
           - x86_64-pc-windows-gnu
           - x86_64-pc-windows-msvc
           - x86_64-apple-darwin
@@ -259,6 +260,9 @@ jobs:
           - target: i686-unknown-linux-musl
             host_os: ubuntu-18.04
 
+          - target: mipsel-unknown-linux-gnu
+            host_os: ubuntu-18.04
+
           - target: x86_64-pc-windows-gnu
             host_os: windows-latest
 
diff --git a/build.rs b/build.rs
index 64d78b8aa9..84010f43a0 100644
--- a/build.rs
+++ b/build.rs
@@ -39,13 +39,13 @@ const RING_SRCS: &[(&[&str], &str)] = &[
     (&[], "crypto/limbs/limbs.c"),
     (&[], "crypto/mem.c"),
     (&[], "crypto/poly1305/poly1305.c"),
+    (&[], "crypto/curve25519/curve25519.c"),
+    (&[], "crypto/fipsmodule/ec/ecp_nistz.c"),
+    (&[], "crypto/fipsmodule/ec/p256.c"),
 
     (&[AARCH64, ARM, X86_64, X86], "crypto/crypto.c"),
-    (&[AARCH64, ARM, X86_64, X86], "crypto/curve25519/curve25519.c"),
-    (&[AARCH64, ARM, X86_64, X86], "crypto/fipsmodule/ec/ecp_nistz.c"),
     (&[AARCH64, ARM, X86_64, X86], "crypto/fipsmodule/ec/gfp_p256.c"),
     (&[AARCH64, ARM, X86_64, X86], "crypto/fipsmodule/ec/gfp_p384.c"),
-    (&[AARCH64, ARM, X86_64, X86], "crypto/fipsmodule/ec/p256.c"),
 
     (&[X86_64, X86], "crypto/cpu-intel.c"),
 
@@ -303,6 +303,10 @@ fn main() {
 fn ring_build_rs_main() {
     use std::env;
 
+    if env::var("CARGO_CFG_TARGET_ENDIAN").unwrap() == "big" {
+        panic!("Big-endian targets are not supported yet");
+    }
+
     let out_dir = env::var("OUT_DIR").unwrap();
     let out_dir = PathBuf::from(out_dir);
 
diff --git a/mk/cargo.sh b/mk/cargo.sh
index 85a1cbc385..9a1b16d1af 100755
--- a/mk/cargo.sh
+++ b/mk/cargo.sh
@@ -20,6 +20,8 @@ IFS=$'\n\t'
 rustflags_self_contained="-Clink-self-contained=yes -Clinker=rust-lld"
 qemu_aarch64="qemu-aarch64 -L /usr/aarch64-linux-gnu"
 qemu_arm="qemu-arm -L /usr/arm-linux-gnueabihf"
+qemu_mipsel="qemu-system-mipsel -L /usr/mipsel-linux-gnu"
+qemu_mips64el="qemu-system-mips64el -L /usr/mips64el-linux-gnu"
 
 # Avoid putting the Android tools in `$PATH` because there are tools in this
 # directory like `clang` that would conflict with the same-named tools that may
@@ -87,6 +89,18 @@ case $target in
     export AR_i686_unknown_linux_musl=llvm-ar-$llvm_version
     export CARGO_TARGET_I686_UNKNOWN_LINUX_MUSL_RUSTFLAGS="$rustflags_self_contained"
     ;;
+  mipsel-unknown-linux-gnu)
+    export CC_mipsel_unknown_linux_gnu=mipsel-linux-gnu-gcc
+    export AR_mipsel_unknown_linux_gnu=mipsel-linux-gnu-gcc-ar
+    export CARGO_TARGET_MIPSEL_UNKNOWN_LINUX_GNU_LINKER=mipsel-linux-gnu-gcc
+    export CARGO_TARGET_MIPSEL_UNKNOWN_LINUX_GNU_RUNNER="$qemu_mipsel"
+    ;;
+  mips64el-unknown-linux-gnuabi64)
+    export CC_mips64el_unknown_linux_gnuabi64=mips64el-linux-gnu-gcc
+    export AR_mips64el_unknown_linux_gnuabi64=mips64el-linux-gnu-gcc-ar
+    export CARGO_TARGET_MIPS64EL_UNKNOWN_LINUX_GNUABI64_LINKER=mips64el-linux-gnu-gcc
+    export CARGO_TARGET_MIPS64EL_UNKNOWN_LINUX_GNUABI64_RUNNER="$qemu_mips64el"
+    ;;
   x86_64-unknown-linux-musl)
     export CC_x86_64_unknown_linux_musl=clang-$llvm_version
     export AR_x86_64_unknown_linux_musl=llvm-ar-$llvm_version
diff --git a/mk/install-build-tools.sh b/mk/install-build-tools.sh
index db50246e8d..87f2dd1921 100755
--- a/mk/install-build-tools.sh
+++ b/mk/install-build-tools.sh
@@ -65,6 +65,18 @@ case $target in
 --target=i686-unknown-linux-musl|--target=x86_64-unknown-linux-musl)
   use_clang=1
   ;;
+--target=mipsel-unknown-linux-gnu)
+  install_packages \
+    qemu-user \
+    gcc-mipsel-linux-gnu \
+    libc6-dev-mipsel-cross
+  ;;
+--target=mips64el-unknown-linux-gnu)
+  install_packages \
+    qemu-user \
+    gcc-mips64el-linux-gnu \
+    libc6-dev-mips64el-cross
+  ;;
 --target=wasm32-unknown-unknown)
   # The version of wasm-bindgen-cli must match the wasm-bindgen version.
   wasm_bindgen_version=$(cargo metadata --format-version 1 | jq -r '.packages | map(select( .name == "wasm-bindgen")) | map(.version) | .[0]')