--- libmalloc/libmalloc-425.100.7/private/malloc_implementation.h
+++ libmalloc/libmalloc-474.0.13/private/malloc_implementation.h
@@ -88,7 +88,7 @@
  * This is SPI that is *not* intended for use elsewhere. It will change
  * and will eventually be removed, without prior warning.
  */
-#if MALLOC_ENABLE_MSL_LITE_SPI
+#if defined(MALLOC_ENABLE_MSL_LITE_SPI) && MALLOC_ENABLE_MSL_LITE_SPI
 
 typedef struct szone_s szone_t;
 
@@ -119,7 +119,7 @@
 	malloc_zone_t *(*basic_zone)(szone_t *zone);
 } _malloc_msl_lite_hooks_t;
 
-#endif // MALLOC_ENABLE_MSL_LITE_SPI
+#endif // defined(MALLOC_ENABLE_MSL_LITE_SPI) && MALLOC_ENABLE_MSL_LITE_SPI
 
 #endif