make master and develop branch names configurable
diff --git a/git-flow-release b/git-flow-release
index 3f5683e..35b4fbe 100755
--- a/git-flow-release
+++ b/git-flow-release
@@ -49,15 +49,15 @@
 	# sanity checks
 	gitflow_check_clean_working_tree
 	git fetch origin
-	gitflow_require_branches_equal develop origin/develop
+	gitflow_require_branches_equal $DEVELOP_BRANCH origin/$DEVELOP_BRANCH
 	gitflow_require_branch_absent $BRANCH
 
 	# create branch
-	git checkout -b $BRANCH develop
+	git checkout -b $BRANCH $DEVELOP_BRANCH
 
 	echo
 	echo "Summary of actions:"
-	echo "- A new branch '$BRANCH' was created, based on 'develop'"
+	echo "- A new branch '$BRANCH' was created, based on '$DEVELOP_BRANCH'"
 	echo "- You are now on branch '$BRANCH'"
 	echo
 	echo "Follow-up actions:"
@@ -75,16 +75,16 @@
 	# sanity checks
 	gitflow_check_clean_working_tree
 	git fetch origin
-	gitflow_require_branches_equal master origin/master
-	gitflow_require_branches_equal develop origin/develop
+	gitflow_require_branches_equal $MASTER_BRANCH origin/$MASTER_BRANCH
+	gitflow_require_branches_equal $DEVELOP_BRANCH origin/$DEVELOP_BRANCH
 
 	# merge into master
-	git checkout master
+	git checkout $MASTER_BRANCH
 	git merge --no-ff $BRANCH
 	git tag v$VERSION
 
 	# merge into develop
-	git checkout develop
+	git checkout $DEVELOP_BRANCH
 	git merge --no-ff $BRANCH
 
 	# delete branch
@@ -96,9 +96,9 @@
 	echo
 	echo "Summary of actions:"
 	echo "- Latest objects have been fetched from 'origin'"
-	echo "- Release branch has been merged into 'master'"
+	echo "- Release branch has been merged into '$MASTER_BRANCH'"
 	echo "- The release was tagged 'v$VERSION'"
-	echo "- Release branch has been back-merged into 'develop'"
+	echo "- Release branch has been back-merged into '$DEVELOP_BRANCH'"
 	echo "- Release branch '$BRANCH' has been deleted"
 	echo
 }