diff --git a/src/wstool/config_yaml.py b/src/wstool/config_yaml.py
index 19f82e5..1f1935a 100644
--- a/src/wstool/config_yaml.py
+++ b/src/wstool/config_yaml.py
@@ -378,7 +378,11 @@ def get_path_spec_from_yaml(yaml_dict):
             elif key == "uri":
                 uri = value
             elif key == "version":
-                version = value
+                # VCs tools expects version to be
+                # string; otherwise, all integer
+                # versions will break application
+                if value is not None: 
+                    version = str(value)
             else:
                 raise MultiProjectException(
                     "Unknown key %s in %s" % (key, yaml_dict))
diff --git a/test/local/test_config_yaml.py b/test/local/test_config_yaml.py
index 305cab2..5a210d1 100644
--- a/test/local/test_config_yaml.py
+++ b/test/local/test_config_yaml.py
@@ -326,6 +326,20 @@ def test_original_syntax_scm(self):
         self.assertEqual(uri, wrap.get_uri())
         self.assertEqual({scmtype: {'local-name': local_name, 'uri': uri}}, wrap.get_legacy_yaml())
 
+        # version is a number
+        local_name = 'common_rosdeps'
+        version = 1234
+        uri = 'https://kforge.ros.org/common/rosdepcore'
+        scmtype = 'hg'
+        struct = {scmtype: {'local-name': local_name, 'version': version, 'uri': uri}}
+        expected_struct = {scmtype: {'local-name': local_name, 'version': str(version), 'uri': uri}}
+        wrap = get_path_spec_from_yaml(struct)
+        self.assertEqual(scmtype, wrap.get_scmtype())
+        self.assertEqual(scmtype, wrap.get_legacy_type())
+        self.assertIsInstance(wrap.get_version(), str)
+        self.assertEqual(uri, wrap.get_uri())
+        self.assertEqual(expected_struct, wrap.get_legacy_yaml())
+
         # no version
         local_name = 'common_rosdeps'
         version = None