diff --git a/include/polarssl/cipher.h b/include/polarssl/cipher.h
index 9452f73..0f6dda5 100644
--- a/include/polarssl/cipher.h
+++ b/include/polarssl/cipher.h
@@ -32,10 +32,10 @@
 
 #include <string.h>
 
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && !defined(inline)
 #define inline _inline
 #else
-#if defined(__ARMCC_VERSION)
+#if defined(__ARMCC_VERSION) && !defined(inline)
 #define inline __inline
 #endif /* __ARMCC_VERSION */
 #endif /*_MSC_VER */