diff --git a/revision.c b/revision.c
index 7ddf0f151a..2ee6886078 100644
--- a/revision.c
+++ b/revision.c
@@ -2650,10 +2650,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 	} else if (!strcmp(arg, "--invert-grep")) {
 		revs->grep_filter.no_body_match = 1;
 	} else if ((argcount = parse_long_opt("encoding", argv, &optarg))) {
+		free(git_log_output_encoding);
 		if (strcmp(optarg, "none"))
 			git_log_output_encoding = xstrdup(optarg);
 		else
-			git_log_output_encoding = "";
+			git_log_output_encoding = xstrdup("");
 		return argcount;
 	} else if (!strcmp(arg, "--reverse")) {
 		revs->reverse ^= 1;
diff --git a/t/t3900-i18n-commit.sh b/t/t3900-i18n-commit.sh
index f27d09cfd9..db7b403bc1 100755
--- a/t/t3900-i18n-commit.sh
+++ b/t/t3900-i18n-commit.sh
@@ -5,6 +5,7 @@
 
 test_description='commit and log output encodings'
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 compare_with () {
diff --git a/t/t3901-i18n-patch.sh b/t/t3901-i18n-patch.sh
index 4b37f78829..5f0b9afc3f 100755
--- a/t/t3901-i18n-patch.sh
+++ b/t/t3901-i18n-patch.sh
@@ -8,6 +8,7 @@ test_description='i18n settings and format-patch | am pipe'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 check_encoding () {