diff --git a/libfuse/lib/fuse_cfg.cpp b/libfuse/lib/fuse_cfg.cpp
index 69949cb0..0bd93f94 100644
--- a/libfuse/lib/fuse_cfg.cpp
+++ b/libfuse/lib/fuse_cfg.cpp
@@ -7,3 +7,9 @@ fuse_cfg_t::valid_uid() const
 {
   return (uid != FUSE_CFG_INVALID_ID);
 }
+
+bool
+fuse_cfg_t::valid_gid() const
+{
+  return (gid != FUSE_CFG_INVALID_ID);
+}