diff --git a/bin/git-bug b/bin/git-bug
index 4ce5437..e6c263f 100755
--- a/bin/git-bug
+++ b/bin/git-bug
@@ -5,7 +5,10 @@ if test "$1" = "finish"; then
   branch=bug/$2
   git merge --no-ff $branch && git delete-branch $branch
 else
-  test -z $1 && echo "bug <name> required." && exit 1
+  test -z $1 && echo "bug <name> required." 1>&2 && exit 1
+  if test -n $2; then
+    echo "too many arguments; if not finishing a bug, only <name> of new bug is expected" && exit 1
+  fi
   branch=bug/$1
   git checkout -b $branch &> /dev/null
 fi
diff --git a/bin/git-feature b/bin/git-feature
index 29aacd0..b2a9129 100755
--- a/bin/git-feature
+++ b/bin/git-feature
@@ -6,6 +6,9 @@ if test "$1" = "finish"; then
   git merge --no-ff $branch && git delete-branch $branch
 else
   test -z $1 && echo "feature <name> required." 1>&2 && exit 1
+  if test -n $2; then
+    echo "too many arguments; if not finishing a feature, only <name> of new feature is expected" && exit 1
+  fi
   branch=feature/$1
   git checkout -b $branch &> /dev/null
 fi
diff --git a/bin/git-refactor b/bin/git-refactor
index e87143a..5898c43 100755
--- a/bin/git-refactor
+++ b/bin/git-refactor
@@ -6,6 +6,9 @@ if test "$1" = "finish"; then
   git merge --no-ff $branch && git delete-branch $branch
 else
   test -z $1 && echo "refactor <name> required." 1>&2 && exit 1
+  if test -n $2; then
+    echo "too many arguments; if not finishing a refactor, only <name> of new refactoring is expected" && exit 1
+  fi
   branch=refactor/$1
   git checkout -b $branch &> /dev/null
 fi