diff --git a/openpype/plugins/publish/validate_sequence_frames.py b/openpype/plugins/publish/validate_sequence_frames.py
index 409d9ac17e..a804a6d9dd 100644
--- a/openpype/plugins/publish/validate_sequence_frames.py
+++ b/openpype/plugins/publish/validate_sequence_frames.py
@@ -33,7 +33,11 @@ class ValidateSequenceFrames(pyblish.api.InstancePlugin):
             if isinstance(repr_files, str):
                 repr_files = [repr_files]
 
-            _, ext = os.path.splitext(repr_files[0])
+            ext = repr.get("ext")
+            if not ext:
+                _, ext = os.path.splitext(repr_files[0])
+            elif not ext.startswith("."):
+                ext = ".{}".format(ext)
             pattern = r"\D?(?P<index>(?P<padding>0*)\d+){}$".format(
                 re.escape(ext))
             patterns = [pattern]
diff --git a/tests/unit/openpype/plugins/publish/test_validate_sequence_frames.py b/tests/unit/openpype/plugins/publish/test_validate_sequence_frames.py
index 232557b76d..e1facdc37b 100644
--- a/tests/unit/openpype/plugins/publish/test_validate_sequence_frames.py
+++ b/tests/unit/openpype/plugins/publish/test_validate_sequence_frames.py
@@ -99,13 +99,12 @@ class TestValidateSequenceFrames(BaseTest):
                 str(excinfo.value))
 
     @pytest.mark.parametrize("files",
-                             ["Main_beauty.1001.v001.ass.gz"])
-    def test_validate_sequence_frames_single_frame_possible_wrong_name(self,
-            instance, plugin, files):
+                             ["Main_beauty.v001.1001.ass.gz"])
+    def test_validate_sequence_frames_single_frame_possible_wrong_name(
+            self, instance, plugin, files):
         # currently pattern fails on extensions with dots
         representations = [
             {
-                "ext": "exr",
                 "files": files,
             }
         ]
@@ -116,6 +115,21 @@ class TestValidateSequenceFrames(BaseTest):
         assert ("Must not have remainder" in
                 str(excinfo.value))
 
+    @pytest.mark.parametrize("files",
+                             ["Main_beauty.v001.1001.ass.gz"])
+    def test_validate_sequence_frames_single_frame_correct_ext(
+            self, instance, plugin, files):
+        # currently pattern fails on extensions with dots
+        representations = [
+            {
+                "ext": "ass.gz",
+                "files": files,
+            }
+        ]
+        instance.data["representations"] = representations
+
+        plugin.process(instance)
+
     def test_validate_sequence_frames_multi_frame(self, instance, plugin):
         representations = [
             {