diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 09d0965..98384ad 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -113,6 +113,12 @@
 
 #endif /* MBEDTLS_CHECK_PARAMS */
 
+#if defined(__GNUC__) || defined(__arm__)
+#define MBEDTLS_ALWAYS_INLINE __attribute__((always_inline))
+#else
+#define MBEDTLS_ALWAYS_INLINE
+#endif
+
 /* Internal helper macros for deprecating API constants. */
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 #if defined(MBEDTLS_DEPRECATED_WARNING)