diff --git a/Documentation/git.txt b/Documentation/git.txt
index 2535a30194..6c19fd1d76 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt
@@ -917,9 +917,9 @@ for full details.
 	avoid issues with stale commit-graphs that contain references to
 	already-deleted commits, but comes with a performance penalty.
 +
-The default is "true", which enables the aforementioned behavior.
-Setting this to "false" disables the existence check. This can lead to
-a performance improvement at the cost of consistency.
+The default is "false", which disables the aforementioned behavior.
+Setting this to "true" enables the existence check so that stale commits
+will never be returned from the commit-graph at the cost of performance.
 
 `GIT_ALLOW_PROTOCOL`::
 	If set to a colon-separated list of protocols, behave as if
diff --git a/commit-graph.c b/commit-graph.c
index acac9bf6e1..6fad9d195d 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1005,7 +1005,7 @@ struct commit *lookup_commit_in_graph(struct repository *repo, const struct obje
 	uint32_t pos;
 
 	if (commit_graph_paranoia == -1)
-		commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
+		commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 0);
 
 	if (!prepare_commit_graph(repo))
 		return NULL;
diff --git a/commit.c b/commit.c
index 8405d7c3fc..37956b836c 100644
--- a/commit.c
+++ b/commit.c
@@ -577,7 +577,7 @@ int repo_parse_commit_internal(struct repository *r,
 		static int commit_graph_paranoia = -1;
 
 		if (commit_graph_paranoia == -1)
-			commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 1);
+			commit_graph_paranoia = git_env_bool(GIT_COMMIT_GRAPH_PARANOIA, 0);
 
 		if (commit_graph_paranoia && !has_object(r, &item->object.oid, 0)) {
 			unparse_commit(r, &item->object.oid);
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 7fe7c72a87..a2b4442660 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -911,10 +911,10 @@ test_expect_success 'stale commit cannot be parsed when given directly' '
 
 		# Verify that it is possible to read the commit from the
 		# commit graph when not being paranoid, ...
-		GIT_COMMIT_GRAPH_PARANOIA=false git rev-list B &&
+		git rev-list B &&
 		# ... but parsing the commit when double checking that
 		# it actually exists in the object database should fail.
-		test_must_fail git rev-list -1 B
+		test_must_fail env GIT_COMMIT_GRAPH_PARANOIA=true git rev-list -1 B
 	)
 '
 
@@ -938,9 +938,9 @@ test_expect_success 'stale commit cannot be parsed when traversing graph' '
 
 		# Again, we should be able to parse the commit when not
 		# being paranoid about commit graph staleness...
-		GIT_COMMIT_GRAPH_PARANOIA=false git rev-parse HEAD~2 &&
+		git rev-parse HEAD~2 &&
 		# ... but fail when we are paranoid.
-		test_must_fail git rev-parse HEAD~2 2>error &&
+		test_must_fail env GIT_COMMIT_GRAPH_PARANOIA=true git rev-parse HEAD~2 2>error &&
 		grep "error: commit $oid exists in commit-graph but not in the object database" error
 	)
 '
diff --git a/t/t6022-rev-list-missing.sh b/t/t6022-rev-list-missing.sh
index 40265a4f66..1ca4eb5a36 100755
--- a/t/t6022-rev-list-missing.sh
+++ b/t/t6022-rev-list-missing.sh
@@ -13,6 +13,11 @@ test_expect_success 'create repository and alternate directory' '
 	test_commit 3
 '
 
+# We manually corrupt the repository, which means that the commit-graph may
+# contain references to already-deleted objects. We thus need to enable
+# commit-graph paranoia to not returned these deleted commits from the graph.
+export GIT_COMMIT_GRAPH_PARANOIA=true
+
 for obj in "HEAD~1" "HEAD~1^{tree}" "HEAD:1.t"
 do
 	test_expect_success "rev-list --missing=error fails with missing object $obj" '
diff --git a/t/t7700-repack.sh b/t/t7700-repack.sh
index d2975e6c93..94f9f4a1da 100755
--- a/t/t7700-repack.sh
+++ b/t/t7700-repack.sh
@@ -271,7 +271,7 @@ test_expect_success 'repacking fails when missing .pack actually means missing o
 		ls .git/objects/pack/*.pack >before-pack-dir &&
 
 		test_must_fail git fsck &&
-		test_must_fail git repack --cruft -d 2>err &&
+		test_must_fail env GIT_COMMIT_GRAPH_PARANOIA=true git repack --cruft -d 2>err &&
 		grep "bad object" err &&
 
 		# Before failing, the repack did not modify the
