diff --git a/library/alignment.h b/library/alignment.h
index 9e1e044..219f4f0 100644
--- a/library/alignment.h
+++ b/library/alignment.h
@@ -15,6 +15,14 @@
 #include <string.h>
 #include <stdlib.h>
 
+#if defined(__GNUC__) && !defined(__ARMCC_VERSION) && !defined(__clang__) \
+    && !defined(__llvm__) && !defined(__INTEL_COMPILER)
+/* Defined if the compiler really is gcc and not clang, etc */
+#define MBEDTLS_COMPILER_IS_GCC
+#define MBEDTLS_GCC_VERSION \
+    (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__)
+#endif
+
 /*
  * Define MBEDTLS_EFFICIENT_UNALIGNED_ACCESS for architectures where unaligned memory
  * accesses are known to be efficient.