diff --git a/t/t3309-notes-merge-auto-resolve.sh b/t/t3309-notes-merge-auto-resolve.sh
index 141d3e4ca4..9bd5dbf341 100755
--- a/t/t3309-notes-merge-auto-resolve.sh
+++ b/t/t3309-notes-merge-auto-resolve.sh
@@ -360,7 +360,12 @@ test_expect_success 'merge z into y with invalid strategy => Fail/No changes' '
 
 test_expect_success 'merge z into y with invalid configuration option => Fail/No changes' '
 	git config core.notesRef refs/notes/y &&
-	test_must_fail git -c notes.mergeStrategy="foo" notes merge z &&
+	cat >expect <<-\EOF &&
+	error: unknown notes merge strategy foo
+	fatal: unable to parse '\''notes.mergeStrategy'\'' from command-line config
+	EOF
+	test_must_fail git -c notes.mergeStrategy="foo" notes merge z 2>actual &&
+	test_cmp expect actual &&
 	# Verify no changes (y)
 	verify_notes y y
 '
diff --git a/t/t5304-prune.sh b/t/t5304-prune.sh
index 8ae314af58..c8fa962b39 100755
--- a/t/t5304-prune.sh
+++ b/t/t5304-prune.sh
@@ -64,8 +64,16 @@ test_expect_success 'gc: implicit prune --expire' '
 '
 
 test_expect_success 'gc: refuse to start with invalid gc.pruneExpire' '
-	git config gc.pruneExpire invalid &&
-	test_must_fail git gc
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	>repo/.git/config &&
+	git -C repo config gc.pruneExpire invalid &&
+	cat >expect <<-\EOF &&
+	error: Invalid gc.pruneexpire: '\''invalid'\''
+	fatal: bad config variable '\''gc.pruneexpire'\'' in file '\''.git/config'\'' at line 2
+	EOF
+	test_must_fail git -C repo gc 2>actual &&
+	test_cmp expect actual
 '
 
 test_expect_success 'gc: start with ok gc.pruneExpire' '
diff --git a/t/t5552-skipping-fetch-negotiator.sh b/t/t5552-skipping-fetch-negotiator.sh
index 165427d57e..b55a9f65e6 100755
--- a/t/t5552-skipping-fetch-negotiator.sh
+++ b/t/t5552-skipping-fetch-negotiator.sh
@@ -3,6 +3,22 @@
 test_description='test skipping fetch negotiator'
 . ./test-lib.sh
 
+test_expect_success 'fetch.negotiationalgorithm config' '
+	test_when_finished "rm -rf repo" &&
+	git init repo &&
+	cat >repo/.git/config <<-\EOF &&
+	[fetch]
+	negotiationAlgorithm
+	EOF
+	cat >expect <<-\EOF &&
+	error: missing value for '\''fetch.negotiationalgorithm'\''
+	fatal: bad config variable '\''fetch.negotiationalgorithm'\'' in file '\''.git/config'\'' at line 2
+	EOF
+	test_expect_code 128 git -C repo fetch >out 2>actual &&
+	test_must_be_empty out &&
+	test_cmp expect actual
+'
+
 have_sent () {
 	while test "$#" -ne 0
 	do