diff --git a/Documentation/config/core.txt b/Documentation/config/core.txt
index 0e8c2832bf..c86b8c8408 100644
--- a/Documentation/config/core.txt
+++ b/Documentation/config/core.txt
@@ -523,7 +523,9 @@ core.commentChar::
 	Commands such as `commit` and `tag` that let you edit
 	messages consider a line that begins with this character
 	commented, and removes them after the editor returns
-	(default '#').
+	(default '#'). Note that this option can take values larger than
+	a byte (whether a single multi-byte character, or you
+	could even go wild with a multi-character sequence).
 +
 If set to "auto", `git-commit` would select a character that is not
 the beginning character of any line in existing commit messages.
diff --git a/config.c b/config.c
index 7e5dbca4bd..92c752ed9f 100644
--- a/config.c
+++ b/config.c
@@ -1565,13 +1565,13 @@ static int git_default_core_config(const char *var, const char *value,
 			return config_error_nonbool(var);
 		else if (!strcasecmp(value, "auto"))
 			auto_comment_line_char = 1;
-		else if (value[0] && !value[1]) {
-			if (value[0] == '\n')
-				return error(_("core.commentChar cannot be newline"));
-			comment_line_str = xstrfmt("%c", value[0]);
+		else if (value[0]) {
+			if (strchr(value, '\n'))
+				return error(_("core.commentChar cannot contain newline"));
+			comment_line_str = xstrdup(value);
 			auto_comment_line_char = 0;
 		} else
-			return error(_("core.commentChar should only be one ASCII character"));
+			return error(_("core.commentChar must have at least one character"));
 		return 0;
 	}
 
diff --git a/t/t0030-stripspace.sh b/t/t0030-stripspace.sh
index e399dd9189..a161faf702 100755
--- a/t/t0030-stripspace.sh
+++ b/t/t0030-stripspace.sh
@@ -403,7 +403,12 @@ test_expect_success 'strip comments with changed comment char' '
 
 test_expect_success 'newline as commentchar is forbidden' '
 	test_must_fail git -c core.commentChar="$LF" stripspace -s 2>err &&
-	grep "core.commentChar cannot be newline" err
+	grep "core.commentChar cannot contain newline" err
+'
+
+test_expect_success 'empty commentchar is forbidden' '
+	test_must_fail git -c core.commentchar= stripspace -s 2>err &&
+	grep "core.commentChar must have at least one character" err
 '
 
 test_expect_success '-c with single line' '
diff --git a/t/t7507-commit-verbose.sh b/t/t7507-commit-verbose.sh
index c3281b192e..4c7db19ce7 100755
--- a/t/t7507-commit-verbose.sh
+++ b/t/t7507-commit-verbose.sh
@@ -101,6 +101,16 @@ test_expect_success 'verbose diff is stripped out with set core.commentChar' '
 	test_grep "Aborting commit due to empty commit message." err
 '
 
+test_expect_success 'verbose diff is stripped with multi-byte comment char' '
+	(
+		GIT_EDITOR=cat &&
+		export GIT_EDITOR &&
+		test_must_fail git -c core.commentchar="foo>" commit -a -v >out 2>err
+	) &&
+	grep "^foo> " out &&
+	test_grep "Aborting commit due to empty commit message." err
+'
+
 test_expect_success 'status does not verbose without --verbose' '
 	git status >actual &&
 	! grep "^diff --git" actual
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index a3c18a4fc2..10ed8b32bc 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -1403,7 +1403,9 @@ test_expect_success "status (core.commentchar with submodule summary)" '
 
 test_expect_success "status (core.commentchar with two chars with submodule summary)" '
 	test_config core.commentchar ";;" &&
-	test_must_fail git -c status.displayCommentPrefix=true status
+	sed "s/^/;/" <expect >expect.double &&
+	git -c status.displayCommentPrefix=true status >output &&
+	test_cmp expect.double output
 '
 
 test_expect_success "--ignore-submodules=all suppresses submodule summary" '