diff --git a/src/gidcache.cpp b/src/gidcache.cpp
index 8a280f51..594e9291 100644
--- a/src/gidcache.cpp
+++ b/src/gidcache.cpp
@@ -28,11 +28,16 @@
 #include <grp.h>
 #include <unistd.h>
 
+#if defined __linux__ and UGID_USE_RWLOCK == 0
+# include <sys/syscall.h>
+#endif
+
 #include <cstdlib>
 #include <algorithm>
 
 #include "gidcache.hpp"
 
+inline
 bool
 gid_t_rec::operator<(const struct gid_t_rec &b) const
 {
@@ -123,21 +128,36 @@ gid_t_cache::cache(const uid_t uid,
   return rec;
 }
 
-void
+static
+inline
+int
+setgroups(const gid_t_rec *rec)
+{
+#if defined __linux__ and UGID_USE_RWLOCK == 0
+  return ::syscall(SYS_setgroups,rec->size,rec->gids);
+#else
+  return ::setgroups(rec->size,rec->gids);
+#endif
+}
+
+int
 gid_t_cache::initgroups(const uid_t uid,
                         const gid_t gid)
 {
+  int rv;
   gid_t_rec *rec;
 
   rec = lower_bound(begin(),end(),uid);
   if(rec == end() || rec->uid != uid)
     {
       rec = cache(uid,gid);
-      ::setgroups(rec->size,rec->gids);
+      rv = ::setgroups(rec);
       std::sort(begin(),end());
     }
   else
     {
-      ::setgroups(rec->size,rec->gids);
+      rv = ::setgroups(rec);
     }
+
+  return rv;
 }
diff --git a/src/gidcache.hpp b/src/gidcache.hpp
index 29ba1c2b..a3b6d44f 100644
--- a/src/gidcache.hpp
+++ b/src/gidcache.hpp
@@ -58,7 +58,7 @@ private:
                     const gid_t gid);
 
 public:
-  void
+  int
   initgroups(const uid_t uid,
              const gid_t gid);
 };
diff --git a/src/ugid.hpp b/src/ugid.hpp
index 4555f333..c1eb34b6 100644
--- a/src/ugid.hpp
+++ b/src/ugid.hpp
@@ -30,15 +30,12 @@
 
 #include <vector>
 
-typedef std::vector<gid_t> gid_t_vector;
-
 namespace mergerfs
 {
   namespace ugid
   {
     void init();
     void initgroups(const uid_t uid, const gid_t gid);
-    void setgroups(const gid_t_vector &gidlist);
   }
 }
 
diff --git a/src/ugid_linux.ipp b/src/ugid_linux.ipp
index 880ca1f8..97a338f1 100644
--- a/src/ugid_linux.ipp
+++ b/src/ugid_linux.ipp
@@ -29,8 +29,6 @@
 
 #include <vector>
 
-typedef std::vector<gid_t> gid_t_vector;
-
 namespace mergerfs
 {
   namespace ugid
@@ -43,11 +41,5 @@ namespace mergerfs
     init()
     {
     }
-
-    int
-    setgroups(const gid_t_vector &gidlist)
-    {
-      return ::syscall(SYS_setgroups,gidlist.size(),&gidlist[0]);
-    }
   }
 }
diff --git a/src/ugid_rwlock.ipp b/src/ugid_rwlock.ipp
index 3b85776c..38d485ca 100644
--- a/src/ugid_rwlock.ipp
+++ b/src/ugid_rwlock.ipp
@@ -29,8 +29,6 @@
 
 #include <vector>
 
-typedef std::vector<gid_t> gid_t_vector;
-
 namespace mergerfs
 {
   namespace ugid
@@ -54,11 +52,5 @@ namespace mergerfs
       currentuid = ::geteuid();
       currentgid = ::getegid();
     }
-
-    int
-    setgroups(const gid_t_vector &gidlist)
-    {
-      return ::setgroups(gidlist.size(),&gidlist[0]);
-    }
   }
 }