src/syscall/syscall_linux.go | 2 +-

diff --git a/src/syscall/syscall_linux.go b/src/syscall/syscall_linux.go
index dfce3d0a4bac336618108e00b7ef0927afbb7029..3387f3bdc2de1ca9836c5f95019e1b0e78e56f87 100644
--- a/src/syscall/syscall_linux.go
+++ b/src/syscall/syscall_linux.go
@@ -109,7 +109,7 @@ 		} else {
 			gid = Getgid()
 		}
 
-		if uint32(gid) == st.Gid || isGroupMember(gid) {
+		if uint32(gid) == st.Gid || isGroupMember(int(st.Gid)) {
 			fmode = (st.Mode >> 3) & 7
 		} else {
 			fmode = st.Mode & 7