diff --git a/exercises/practice/raindrops/raindrops.h b/exercises/practice/raindrops/raindrops.h
index 3cf9b4c8..61505644 100644
--- a/exercises/practice/raindrops/raindrops.h
+++ b/exercises/practice/raindrops/raindrops.h
@@ -1,6 +1,6 @@
 #ifndef RAINDROPS_H
 #define RAINDROPS_H
 
-char *convert(char result[], int drops);
+void convert(char result[], int drops);
 
 #endif