diff --git a/src/iu_helpers.c b/src/iu_helpers.c
index fee51bc..bc87905 100644
--- a/src/iu_helpers.c
+++ b/src/iu_helpers.c
@@ -1,4 +1,5 @@
 #include <stdint.h>
+#include <string.h>
 
 #include <osmocom/core/utils.h>