diff --git a/src/libstrongswan/utils/enumerator.c b/src/libstrongswan/utils/enumerator.c
index d4d32fb6f..48c0b5484 100644
--- a/src/libstrongswan/utils/enumerator.c
+++ b/src/libstrongswan/utils/enumerator.c
@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <dirent.h>
 #include <errno.h>
+#include <string.h>
 
 #include <debug.h>