diff --git a/tests/unit/core/test-core-command.cpp b/tests/unit/core/test-core-command.cpp
index 01bb152f8..22d70d51b 100644
--- a/tests/unit/core/test-core-command.cpp
+++ b/tests/unit/core/test-core-command.cpp
@@ -31,6 +31,7 @@ extern "C"
 #ifndef HAVE_CONFIG_H
 #define HAVE_CONFIG_H
 #endif
+#include <string.h>
 #include "src/core/weechat.h"
 #include "src/core/core-command.h"
 #include "src/core/core-input.h"