1 files changed, 2 insertions, 1 deletions

diff --git a/crc32.c b/crc32.c
index 166330d0..97eb5fda 100644
--- a/crc32.c
+++ b/crc32.c
@@ -106,7 +106,8 @@
 #endif
 
 /* If available, use the ARM processor CRC32 instruction. */
-#if defined(__aarch64__) && defined(__ARM_FEATURE_CRC32) && W == 8
+#if defined(__aarch64__) && defined(__ARM_FEATURE_CRC32) && \
+    defined(W) && W == 8
 #  define ARMCRC32
 #endif