diff --git a/git-compat-util.h b/git-compat-util.h
index 36a25ae252..c6669db07d 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -189,6 +189,12 @@ struct strbuf;
 #define _NETBSD_SOURCE 1
 #define _SGI_SOURCE 1
 
+#if defined(__GNUC__)
+#define UNUSED(var) UNUSED_##var __attribute__((unused))
+#else
+#define UNUSED(var) UNUSED_##var
+#endif
+
 #if defined(WIN32) && !defined(__CYGWIN__) /* Both MinGW and MSVC */
 # if !defined(_WIN32_WINNT)
 #  define _WIN32_WINNT 0x0600