diff --git a/rest_framework/versioning.py b/rest_framework/versioning.py
index 78cfc9dc81..c6df091d56 100644
--- a/rest_framework/versioning.py
+++ b/rest_framework/versioning.py
@@ -135,7 +135,10 @@ def reverse(self, viewname, args=None, kwargs=None, request=None, format=None, *
         )
 
     def get_versioned_viewname(self, viewname, request):
-        return request.version + ':' + viewname
+        if ":" not in viewname:
+            return request.version + ":" + viewname
+        else:
+            return viewname
 
 
 class HostNameVersioning(BaseVersioning):