diff --git a/git-merge.sh b/git-merge.sh
index ba4226042..477002910 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -8,6 +8,9 @@ USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commi
 . git-sh-setup
 set_reflog_action "merge $*"
 
+test -z "$(git ls-files -u)" ||
+	die "You are in a middle of conflicted merge."
+
 LF='
 '
 
diff --git a/git-pull.sh b/git-pull.sh
index 28d08195f..c184fb81a 100755
--- a/git-pull.sh
+++ b/git-pull.sh
@@ -9,6 +9,9 @@ LONG_USAGE='Fetch one or more remote refs and merge it/them into the current HEA
 . git-sh-setup
 set_reflog_action "pull $*"
 
+test -z "$(git ls-files -u)" ||
+	die "You are in a middle of conflicted merge."
+
 strategy_args= no_summary= no_commit= squash=
 while case "$#,$1" in 0) break ;; *,-*) ;; *) break ;; esac
 do