diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index f82694a..8f04885 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -36,6 +36,7 @@
 
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 #include <unistd.h>
+#include <strings.h>
 #endif
 
 /*----------------------------------------------------------------------------*/