diff --git a/cabal-testsuite/PackageTests/ForeignLibs/UseLib.c b/cabal-testsuite/PackageTests/ForeignLibs/UseLib.c
index 2ed882fe9a6cc275f1587d8c901e9a0a2a77c87c..5441e469bd1d93fe9c9212de436dbfde063bbe12 100644
--- a/cabal-testsuite/PackageTests/ForeignLibs/UseLib.c
+++ b/cabal-testsuite/PackageTests/ForeignLibs/UseLib.c
@@ -4,7 +4,7 @@
 /* Forward declarations */
 bool myForeignLibInit();
 void myForeignLibExit();
-void sayHi();
+extern void sayHi();
 
 int main()
 {