diff --git a/t/t1300-config.sh b/t/t1300-config.sh
index e8b4575758..e5fb9114f6 100755
--- a/t/t1300-config.sh
+++ b/t/t1300-config.sh
@@ -1710,18 +1710,23 @@ test_expect_success '--show-origin getting a single key' '
 '
 
 test_expect_success 'set up custom config file' '
-	CUSTOM_CONFIG_FILE="file\" (dq) and spaces.conf" &&
+	CUSTOM_CONFIG_FILE="custom.conf" &&
 	cat >"$CUSTOM_CONFIG_FILE" <<-\EOF
 	[user]
 		custom = true
 	EOF
 '
 
+test_expect_success !MINGW 'set up custom config file with special name characters' '
+	WEIRDLY_NAMED_FILE="file\" (dq) and spaces.conf" &&
+	cp "$CUSTOM_CONFIG_FILE" "$WEIRDLY_NAMED_FILE"
+'
+
 test_expect_success !MINGW '--show-origin escape special file name characters' '
 	cat >expect <<-\EOF &&
 	file:"file\" (dq) and spaces.conf"	user.custom=true
 	EOF
-	git config --file "$CUSTOM_CONFIG_FILE" --show-origin --list >output &&
+	git config --file "$WEIRDLY_NAMED_FILE" --show-origin --list >output &&
 	test_cmp expect output
 '
 
@@ -1747,7 +1752,7 @@ test_expect_success '--show-origin stdin with file include' '
 	test_cmp expect output
 '
 
-test_expect_success !MINGW '--show-origin blob' '
+test_expect_success '--show-origin blob' '
 	blob=$(git hash-object -w "$CUSTOM_CONFIG_FILE") &&
 	cat >expect <<-EOF &&
 	blob:$blob	user.custom=true
@@ -1756,9 +1761,9 @@ test_expect_success !MINGW '--show-origin blob' '
 	test_cmp expect output
 '
 
-test_expect_success !MINGW '--show-origin blob ref' '
+test_expect_success '--show-origin blob ref' '
 	cat >expect <<-\EOF &&
-	blob:"master:file\" (dq) and spaces.conf"	user.custom=true
+	blob:master:custom.conf	user.custom=true
 	EOF
 	git add "$CUSTOM_CONFIG_FILE" &&
 	git commit -m "new config file" &&