diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 3c3de3a156f..fb8e166a26f 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -263,7 +263,6 @@ static int graph_write(int argc, const char **argv)
 	    git_env_bool(GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS, 0))
 		flags |= COMMIT_GRAPH_WRITE_BLOOM_FILTERS;
 
-	read_replace_refs = 0;
 	odb = find_odb(the_repository, opts.obj_dir);
 
 	if (opts.reachable) {
@@ -318,6 +317,7 @@ int cmd_commit_graph(int argc, const char **argv, const char *prefix)
 	if (!argc)
 		goto usage;
 
+	read_replace_refs = 0;
 	save_commit_buffer = 0;
 
 	if (!strcmp(argv[0], "verify"))
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 295c5bd94d2..84d122a7ae7 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -70,8 +70,8 @@ test_expect_success 'create commits and repack' '
 '
 
 graph_git_two_modes() {
-	git -c core.commitGraph=true $1 >output
-	git -c core.commitGraph=false $1 >expect
+	git -c core.commitGraph=true $1 >output &&
+	git -c core.commitGraph=false $1 >expect &&
 	test_cmp expect output
 }
 
@@ -385,6 +385,7 @@ test_expect_success 'replace-objects invalidates commit-graph' '
 		git commit-graph write --reachable &&
 		test_path_is_file .git/objects/info/commit-graph &&
 		git replace HEAD~1 HEAD~2 &&
+		graph_git_two_modes "commit-graph verify" &&
 		git -c core.commitGraph=false log >expect &&
 		git -c core.commitGraph=true log >actual &&
 		test_cmp expect actual &&
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 587226ed103..847b8097109 100755
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -55,8 +55,8 @@ test_expect_success 'create commits and write commit-graph' '
 '
 
 graph_git_two_modes() {
-	git -c core.commitGraph=true $1 >output
-	git -c core.commitGraph=false $1 >expect
+	git ${2:+ -C "$2"} -c core.commitGraph=true $1 >output &&
+	git ${2:+ -C "$2"} -c core.commitGraph=false $1 >expect &&
 	test_cmp expect output
 }
 
@@ -64,12 +64,13 @@ graph_git_behavior() {
 	MSG=$1
 	BRANCH=$2
 	COMPARE=$3
+	DIR=$4
 	test_expect_success "check normal git operations: $MSG" '
-		graph_git_two_modes "log --oneline $BRANCH" &&
-		graph_git_two_modes "log --topo-order $BRANCH" &&
-		graph_git_two_modes "log --graph $COMPARE..$BRANCH" &&
-		graph_git_two_modes "branch -vv" &&
-		graph_git_two_modes "merge-base -a $BRANCH $COMPARE"
+		graph_git_two_modes "log --oneline $BRANCH" "$DIR" &&
+		graph_git_two_modes "log --topo-order $BRANCH" "$DIR" &&
+		graph_git_two_modes "log --graph $COMPARE..$BRANCH" "$DIR" &&
+		graph_git_two_modes "branch -vv" "$DIR" &&
+		graph_git_two_modes "merge-base -a $BRANCH $COMPARE" "$DIR"
 	'
 }
 
@@ -187,7 +188,10 @@ test_expect_success 'create fork and chain across alternate' '
 	)
 '
 
-graph_git_behavior 'alternate: commit 13 vs 6' commits/13 commits/6
+if test -d fork
+then
+	graph_git_behavior 'alternate: commit 13 vs 6' commits/13 origin/commits/6 "fork"
+fi
 
 test_expect_success 'test merge stragety constants' '
 	git clone . merge-2 &&