diff --git a/tests/unit/plugins/irc/test-irc-join.cpp b/tests/unit/plugins/irc/test-irc-join.cpp
index 43e9c0d5c..2359ff651 100644
--- a/tests/unit/plugins/irc/test-irc-join.cpp
+++ b/tests/unit/plugins/irc/test-irc-join.cpp
@@ -25,6 +25,7 @@
 
 extern "C"
 {
+#include <string.h>
 #include "src/core/wee-arraylist.h"
 #include "src/core/wee-config-file.h"
 #include "src/plugins/irc/irc-channel.h"