diff --git a/sys/dev/cxgbe/adapter.h b/sys/dev/cxgbe/adapter.h
index 05d22253c18..804954b41f2 100644
--- a/sys/dev/cxgbe/adapter.h
+++ b/sys/dev/cxgbe/adapter.h
@@ -72,7 +72,7 @@ prefetch(void *x)
 	__asm volatile("prefetcht0 %0" :: "m" (*(unsigned long *)x));
 }
 #else
-#define prefetch(x)
+#define prefetch(x) __builtin_prefetch(x)
 #endif
 
 #ifndef SYSCTL_ADD_UQUAD