diff --git a/android/BuildInstructions.md b/android/BuildInstructions.md
index fdbea867150c..39cf2ad7715c 100644
--- a/android/BuildInstructions.md
+++ b/android/BuildInstructions.md
@@ -128,6 +128,8 @@ Linux distro:
 #### 5. Install and configure Rust toolchain
 
 - Get the latest **stable** Rust toolchain via [rustup.rs](https://rustup.rs/).
+  Also install `cbindgen` which is required to build `wireguard-go-rs`:
+  `cargo install --force cbindgen`
 
 - Configure Android cross-compilation targets and set up linker and archiver. This can be done by setting the following
 environment variables:
diff --git a/android/docs/BuildInstructions.macos.md b/android/docs/BuildInstructions.macos.md
index 01546c570ac6..cf26a297d862 100644
--- a/android/docs/BuildInstructions.macos.md
+++ b/android/docs/BuildInstructions.macos.md
@@ -28,6 +28,11 @@ Finish the install of `rustup`:
 rustup-init
 ```
 
+Install `cbindgen` which is required to build `wireguard-go-rs`:
+```bash
+cargo install --force cbindgen
+```
+
 ## 2. Install SDK Tools and Android NDK Toolchain
 Open Android Studio -> Tools -> SDK Manager, and install `Android SDK Command-line Tools (latest)`.