diff --git a/rhodecode/lib/vcs/backends/base.py b/rhodecode/lib/vcs/backends/base.py
index b53f5a3d..135876a5 100644
--- a/rhodecode/lib/vcs/backends/base.py
+++ b/rhodecode/lib/vcs/backends/base.py
@@ -104,6 +104,10 @@ class MergeFailureReason(object):
     # The source repo reference is missing.
     MISSING_SOURCE_REF = 10
 
+    # The merge was not successful, there are conflicts related to sub
+    # repositories.
+    SUBREPO_MERGE_FAILED = 11
+
 
 class UpdateFailureReason(object):
     """
diff --git a/rhodecode/model/pull_request.py b/rhodecode/model/pull_request.py
index 9e87ef51..6d3d36e0 100644
--- a/rhodecode/model/pull_request.py
+++ b/rhodecode/model/pull_request.py
@@ -105,6 +105,9 @@ class PullRequestModel(BaseModel):
         MergeFailureReason.MISSING_SOURCE_REF: lazy_ugettext(
             'This pull request cannot be merged because the source '
             'reference is missing.'),
+        MergeFailureReason.SUBREPO_MERGE_FAILED: lazy_ugettext(
+            'This pull request cannot be merged because of conflicts related '
+            'to sub repositories.'),
     }
 
     UPDATE_STATUS_MESSAGES = {