diff --git a/ares_nowarn.c b/ares_nowarn.c
index 51662228..0c77771b 100644
--- a/ares_nowarn.c
+++ b/ares_nowarn.c
@@ -17,6 +17,10 @@
 
 #include "ares_setup.h"
 
+#ifdef HAVE_ASSERT_H
+#  include <assert.h>
+#endif
+
 #include "ares_nowarn.h"
 
 #if (SIZEOF_INT == 2)