diff --git a/tests/Standardscompliance/bz531160-ldd-Vulnerable-to-Social-Engineering-Exploits/interp.c b/tests/Standardscompliance/bz531160-ldd-Vulnerable-to-Social-Engineering-Exploits/interp.c
index 965d3d1..4030866 100644
--- a/tests/Standardscompliance/bz531160-ldd-Vulnerable-to-Social-Engineering-Exploits/interp.c
+++ b/tests/Standardscompliance/bz531160-ldd-Vulnerable-to-Social-Engineering-Exploits/interp.c
@@ -1,3 +1,5 @@
+#include <unistd.h>
+
 #define MESG "you are not suppposed to see this\n"
 
 int main()