diff --git a/src/multiplication/multiplication.c b/src/multiplication/multiplication.c
index aee181c..f61ca18 100644
--- a/src/multiplication/multiplication.c
+++ b/src/multiplication/multiplication.c
@@ -1,3 +1,4 @@
+#include "multiplication.h"
 int multiply(int a, int b) {
     if (a==0||b==0) return 0;
     else return a * b;