diff --git a/src/lib/Hydra/Controller/API.pm b/src/lib/Hydra/Controller/API.pm
index 5a67b39c..69d85f7c 100644
--- a/src/lib/Hydra/Controller/API.pm
+++ b/src/lib/Hydra/Controller/API.pm
@@ -217,7 +217,7 @@ sub scmdiff : Chained('api') PathPart('scmdiff') Args(0) {
     if($type eq "hg") {
         my $clonePath = scmPath . "/" . sha256_hex($uri);
         die if ! -d $clonePath;
-        $branch = `hg log --template '{branch}' -r $rev2`;
+        $branch = `(cd $clonePath ; hg log --template '{branch}' -r $rev2)`;
 	$diff .= `(cd $clonePath ; hg log -r $rev1 -r $rev2 -b $branch)`;
 	$diff .= `(cd $clonePath ; hg diff -r $rev1:$rev2)`;
     } elsif ($type eq "git") {