diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index 7225abd81122e6..78f3647ed974b0 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -46,9 +46,11 @@ show_tool_names () {
 		while read scriptname
 		do
 			setup_tool "$scriptname" 2>/dev/null
-			variants="$variants$(list_tool_variants)\n"
+			# We need an actual line feed here
+			variants="$variants
+$(list_tool_variants)"
 		done
-		variants="$(echo "$variants" | sort | uniq)"
+		variants="$(echo "$variants" | sort -u)"
 
 		for toolname in $variants
 		do
diff --git a/t/t7610-mergetool.sh b/t/t7610-mergetool.sh
index 70afdd06fa7208..6ac75b5d4c0a40 100755
--- a/t/t7610-mergetool.sh
+++ b/t/t7610-mergetool.sh
@@ -828,4 +828,15 @@ test_expect_success 'mergetool -Oorder-file is honored' '
 	test_cmp expect actual
 '
 
+test_expect_success 'mergetool --tool-help shows recognized tools' '
+	# Check a few known tools are correctly shown
+	git mergetool --tool-help >mergetools &&
+	grep vimdiff mergetools &&
+	grep vimdiff3 mergetools &&
+	grep gvimdiff2 mergetools &&
+	grep araxis mergetools &&
+	grep xxdiff mergetools &&
+	grep meld mergetools
+'
+
 test_done