diff --git a/merge-recursive.c b/merge-recursive.c
index 8f72b2c079..4a82b741ae 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -680,6 +680,12 @@ static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
 {
 	xpparam_t xpp;
 
+	if (buffer_is_binary(orig->ptr, orig->size) ||
+			buffer_is_binary(src1->ptr, src1->size) ||
+			buffer_is_binary(src2->ptr, src2->size))
+		return error("Cannot merge binary files: %s vs. %s\n",
+			name1, name2);
+
 	memset(&xpp, 0, sizeof(xpp));
 	return xdl_merge(orig,
 			 src1, name1,
diff --git a/t/t6024-recursive-merge.sh b/t/t6024-recursive-merge.sh
index a398556137..058db9cc52 100755
--- a/t/t6024-recursive-merge.sh
+++ b/t/t6024-recursive-merge.sh
@@ -81,4 +81,18 @@ EOF
 
 test_expect_success "virtual trees were processed" "git diff expect out"
 
+git reset --hard
+test_expect_success 'refuse to merge binary files' '
+	printf "\0" > binary-file &&
+	git add binary-file &&
+	git commit -m binary &&
+	git checkout G &&
+	printf "\0\0" > binary-file &&
+	git add binary-file &&
+	git commit -m binary2 &&
+	! git merge F > merge.out 2> merge.err &&
+	grep "Cannot merge binary files: HEAD:binary-file vs. F:binary-file" \
+		merge.err
+'
+
 test_done