diff --git a/library/bn_mul.h b/library/bn_mul.h
index 6b8106f..a34a7c7 100644
--- a/library/bn_mul.h
+++ b/library/bn_mul.h
@@ -82,9 +82,11 @@
 
 #if defined(MBEDTLS_HAVE_ASM)
 
+/* *INDENT-OFF* */
 #ifndef asm
 #define asm __asm
 #endif
+/* *INDENT-ON* */
 
 /* armcc5 --gnu defines __GNUC__ but doesn't support GNU's extended asm */
 #if defined(__GNUC__) && \