diff --git a/mathml2omml/__init__.py b/mathml2omml/__init__.py
index f9bcde4..122f5d2 100644
--- a/mathml2omml/__init__.py
+++ b/mathml2omml/__init__.py
@@ -747,7 +747,7 @@ def to_str(self):
                     '<m:groupChrPr>'
                     '<m:chr m:val="%s"/>'
                     '<m:pos m:val="bot"/>'
-                    '</m:groupChr>'
+                    '</m:groupChrPr>'
                     '%s'
                     '</m:groupChr>') % (underscript.escape_text(), base)
         return ('<m:limLow>'
@@ -784,7 +784,7 @@ def to_str(self):
                     '<m:groupChrPr>'
                     '<m:chr m:val="%s"/>'
                     '<m:pos m:val="top"/>'
-                    '</m:groupChr>'
+                    '</m:groupChrPr>'
                     '%s'
                     '</m:groupChr>') % (overscript.escape_text(), base)
         return ('<m:limUpp>'
diff --git a/tests/test_converter.py b/tests/test_converter.py
index 3a2140f..cd5d11b 100644
--- a/tests/test_converter.py
+++ b/tests/test_converter.py
@@ -234,3 +234,25 @@ def test_matrix1(self):
             '</m:e></m:box></m:e>'
             '</m:mr>'
             '</m:m></m:e></m:box></m:oMath>')
+
+    def test_vector_operator(self):
+        """Test for vector operator (GitHub issue #2)"""
+        mathml = '<math><mover><mi>AB</mi><mo stretchy="true" accent="true">→</mo></mover></math>'
+        
+        result = mathml2omml.convert(mathml)
+        print(result)
+        # The result should contain properly closed groupChrPr tags
+        self.assertIn('</m:groupChrPr>', result)
+        self.assertIn('<m:groupChr>', result)
+        self.assertIn('</m:groupChr>', result)
+
+    def test_underscript_accent(self):
+        """Test for underscript with stretchy accent (GitHub issue #2)"""
+        mathml = '<math><munder><mi>AB</mi><mo stretchy="true" accent="true">_</mo></munder></math>'
+        
+        result = mathml2omml.convert(mathml)
+        
+        # The result should contain properly closed groupChrPr tags
+        self.assertIn('</m:groupChrPr>', result)
+        self.assertIn('<m:groupChr>', result)
+        self.assertIn('</m:groupChr>', result)
\ No newline at end of file