diff --git a/scrutiny/projects/models.py b/scrutiny/projects/models.py
index 1eb85e2..896d847 100644
--- a/scrutiny/projects/models.py
+++ b/scrutiny/projects/models.py
@@ -164,14 +164,14 @@ class Module(models.Model):
             cmd.append('--grep')
             cmd.append(grep)
 
-        def get_ref(v):
-            if re.findall(r'\.g([0-9a-f]{7,12})', v):
-                return re.findall(r'\.g([0-9a-f]{7,12})', v)[0]
-            if re.findall(r'\+g([0-9a-f]{7,12})', v):
-                return re.findall(r'\+g([0-9a-f]{7,12})', v)[0]
+        def get_ref(version_number):
+            if re.findall(r'\.g([0-9a-f]{7,12})', version_number):
+                return re.findall(r'\.g([0-9a-f]{7,12})', version_number)[0]
+            if re.findall(r'\+g([0-9a-f]{7,12})', version_number):
+                return re.findall(r'\+g([0-9a-f]{7,12})', version_number)[0]
             if re.findall(r'\-g([0-9a-f]{7,12})', version_number):
                 return re.findall(r'\-g([0-9a-f]{7,12})', version_number)[0]
-            return 'v' + v
+            return 'v' + version_number
 
         cmd.append('%s...%s' % (get_ref(v1), get_ref(v2)))