diff --git a/src/client/mac/handler/dynamic_images.cc b/src/client/mac/handler/dynamic_images.cc
index 73c013d4..1d5f1f9b 100644
--- a/src/client/mac/handler/dynamic_images.cc
+++ b/src/client/mac/handler/dynamic_images.cc
@@ -34,6 +34,7 @@ extern "C" { // needed to compile on Leopard
 }
 
 #include "breakpad_nlist_64.h"
+#include <assert.h>
 #include <dlfcn.h>
 #include <mach/mach_vm.h>
 #include <algorithm>