diff --git a/src/sections.zig b/src/sections.zig
index 015dced..183a22e 100644
--- a/src/sections.zig
+++ b/src/sections.zig
@@ -466,6 +466,22 @@ test "userGids" {
 
     var user_gids = try userGids(allocator, &corpus);
     defer user_gids.deinit(allocator);
+
+    for (corpus.users) |user| {
+        const groups = corpus.username2groups.get(user.name);
+        const offset = user_gids.name2offset.get(user.name);
+        if (groups == null) {
+            try testing.expect(offset == null);
+            continue;
+        }
+        var vit = try compress.VarintSliceIterator(user_gids.blob[offset.?..]);
+        var it = compress.DeltaDecompressionIterator(&vit);
+        try testing.expectEqual(it.remaining(), groups.?.len);
+        var i: usize = 0;
+        while (try it.next()) |gid| : (i += 1) {
+            try testing.expectEqual(gid, groups.?[i].gid);
+        }
+    }
 }
 
 test "pack gids" {