diff --git a/cc/builder.go b/cc/builder.go
index 721d478..e7c08b7 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -29,6 +29,7 @@
 )
 
 const (
+	objectExtension        = ".o"
 	sharedLibraryExtension = ".so"
 	staticLibraryExtension = ".a"
 )