diff --git a/third-party/fdlibm/include/fdlibm.h b/third-party/fdlibm/include/fdlibm.h
index 817f22a8c..fcee3cfeb 100644
--- a/third-party/fdlibm/include/fdlibm.h
+++ b/third-party/fdlibm/include/fdlibm.h
@@ -13,7 +13,8 @@
 /* Sometimes it's necessary to define __LITTLE_ENDIAN explicitly
    but these catch some common cases. */
 
-#if defined(i386) || defined(i486) || \
+#if defined(i386) || defined(__i386) || defined(__i386__) || \
+	defined(i486) || defined(__i486) || defined(__i486__) || \
 	defined(intel) || defined(x86) || defined(i86pc) || \
 	defined(__alpha) || defined(__osf__) || \
 	defined(__x86_64__) || defined(__arm__)