diff --git a/revision.c b/revision.c
index 7ff61ff5f73db07af522ac57d62ed9e699aedf72..c96265d89dea5f1df6094621e68a164239e4f9f6 100644
--- a/revision.c
+++ b/revision.c
@@ -1991,6 +1991,7 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 	} else if (!strcmp(arg, "--extended-regexp") || !strcmp(arg, "-E")) {
 		revs->grep_filter.pattern_type_option = GREP_PATTERN_TYPE_ERE;
 	} else if (!strcmp(arg, "--regexp-ignore-case") || !strcmp(arg, "-i")) {
+		revs->grep_filter.ignore_case = 1;
 		revs->grep_filter.regflags |= REG_ICASE;
 		DIFF_OPT_SET(&revs->diffopt, PICKAXE_IGNORE_CASE);
 	} else if (!strcmp(arg, "--fixed-strings") || !strcmp(arg, "-F")) {
diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index a8dce0ca2dba4e294b91ca98a1304c88e38c5d19..547f4c19a71511933ef308c2378283dc1b4114e0 100755
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -231,14 +231,47 @@ second
 initial
 EOF
 test_expect_success 'log --invert-grep --grep' '
-	git log --pretty="tformat:%s" --invert-grep --grep=th --grep=Sec >actual &&
-	test_cmp expect actual
+	# Fixed
+	git -c grep.patternType=fixed log --pretty="tformat:%s" --invert-grep --grep=th --grep=Sec >actual &&
+	test_cmp expect actual &&
+
+	# POSIX basic
+	git -c grep.patternType=basic log --pretty="tformat:%s" --invert-grep --grep=t[h] --grep=S[e]c >actual &&
+	test_cmp expect actual &&
+
+	# POSIX extended
+	git -c grep.patternType=basic log --pretty="tformat:%s" --invert-grep --grep=t[h] --grep=S[e]c >actual &&
+	test_cmp expect actual &&
+
+	# PCRE
+	if test_have_prereq PCRE
+	then
+		git -c grep.patternType=perl log --pretty="tformat:%s" --invert-grep --grep=t[h] --grep=S[e]c >actual &&
+		test_cmp expect actual
+	fi
 '
 
 test_expect_success 'log --invert-grep --grep -i' '
 	echo initial >expect &&
-	git log --pretty="tformat:%s" --invert-grep -i --grep=th --grep=Sec >actual &&
-	test_cmp expect actual
+
+	# Fixed
+	git -c grep.patternType=fixed log --pretty="tformat:%s" --invert-grep -i --grep=th --grep=Sec >actual &&
+	test_cmp expect actual &&
+
+	# POSIX basic
+	git -c grep.patternType=basic log --pretty="tformat:%s" --invert-grep -i --grep=t[h] --grep=S[e]c >actual &&
+	test_cmp expect actual &&
+
+	# POSIX extended
+	git -c grep.patternType=extended log --pretty="tformat:%s" --invert-grep -i --grep=t[h] --grep=S[e]c >actual &&
+	test_cmp expect actual &&
+
+	# PCRE
+	if test_have_prereq PCRE
+	then
+		git -c grep.patternType=perl log --pretty="tformat:%s" --invert-grep -i --grep=t[h] --grep=S[e]c >actual &&
+		test_cmp expect actual
+	fi
 '
 
 test_expect_success 'log --grep option parsing' '
@@ -256,8 +289,25 @@ test_expect_success 'log -i --grep' '
 
 test_expect_success 'log --grep -i' '
 	echo Second >expect &&
+
+	# Fixed
 	git log -1 --pretty="tformat:%s" --grep=sec -i >actual &&
-	test_cmp expect actual
+	test_cmp expect actual &&
+
+	# POSIX basic
+	git -c grep.patternType=basic log -1 --pretty="tformat:%s" --grep=s[e]c -i >actual &&
+	test_cmp expect actual &&
+
+	# POSIX extended
+	git -c grep.patternType=extended log -1 --pretty="tformat:%s" --grep=s[e]c -i >actual &&
+	test_cmp expect actual &&
+
+	# PCRE
+	if test_have_prereq PCRE
+	then
+		git -c grep.patternType=perl log -1 --pretty="tformat:%s" --grep=s[e]c -i >actual &&
+		test_cmp expect actual
+	fi
 '
 
 test_expect_success 'log -F -E --grep=<ere> uses ere' '