diff --git a/library/padlock.c b/library/padlock.c
index 3e9f9a9..e980d24 100644
--- a/library/padlock.c
+++ b/library/padlock.c
@@ -38,6 +38,10 @@
 
 #include <string.h>
 
+#ifndef asm
+#define asm __asm
+#endif
+
 #if defined(MBEDTLS_HAVE_X86)
 
 /*