diff --git a/builtin/grep.c b/builtin/grep.c
index 462e607901..ae738312aa 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -386,7 +386,7 @@ static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int
 
 	for (nr = 0; nr < active_nr; nr++) {
 		const struct cache_entry *ce = active_cache[nr];
-		if (!S_ISREG(ce->ce_mode) || ce_intent_to_add(ce))
+		if (!S_ISREG(ce->ce_mode))
 			continue;
 		if (!ce_path_match(ce, pathspec, NULL))
 			continue;
@@ -396,7 +396,7 @@ static int grep_cache(struct grep_opt *opt, const struct pathspec *pathspec, int
 		 * cache version instead
 		 */
 		if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
-			if (ce_stage(ce))
+			if (ce_stage(ce) || ce_intent_to_add(ce))
 				continue;
 			hit |= grep_sha1(opt, ce->sha1, ce->name, 0, ce->name);
 		}
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index bd8ea1191f..cf3f9ec631 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -177,7 +177,7 @@ do
 
 	test_expect_success "grep -c $L (no /dev/null)" '
 		! git grep -c test $H | grep /dev/null
-        '
+	'
 
 	test_expect_success "grep --max-depth -1 $L" '
 		{
@@ -1377,4 +1377,62 @@ test_expect_success 'grep --color -e A --and -e B -p with context' '
 	test_cmp expected actual
 '
 
+test_expect_success 'grep can find things only in the work tree' '
+	: >work-tree-only &&
+	git add work-tree-only &&
+	test_when_finished "git rm -f work-tree-only" &&
+	echo "find in work tree" >work-tree-only &&
+	git grep --quiet "find in work tree" &&
+	test_must_fail git grep --quiet --cached "find in work tree" &&
+	test_must_fail git grep --quiet "find in work tree" HEAD
+'
+
+test_expect_success 'grep can find things only in the work tree (i-t-a)' '
+	echo "intend to add this" >intend-to-add &&
+	git add -N intend-to-add &&
+	test_when_finished "git rm -f intend-to-add" &&
+	git grep --quiet "intend to add this" &&
+	test_must_fail git grep --quiet --cached "intend to add this" &&
+	test_must_fail git grep --quiet "intend to add this" HEAD
+'
+
+test_expect_success 'grep does not search work tree with assume unchanged' '
+	echo "intend to add this" >intend-to-add &&
+	git add -N intend-to-add &&
+	git update-index --assume-unchanged intend-to-add &&
+	test_when_finished "git rm -f intend-to-add" &&
+	test_must_fail git grep --quiet "intend to add this" &&
+	test_must_fail git grep --quiet --cached "intend to add this" &&
+	test_must_fail git grep --quiet "intend to add this" HEAD
+'
+
+test_expect_success 'grep can find things only in the index' '
+	echo "only in the index" >cache-this &&
+	git add cache-this &&
+	rm cache-this &&
+	test_when_finished "git rm --cached cache-this" &&
+	test_must_fail git grep --quiet "only in the index" &&
+	git grep --quiet --cached "only in the index" &&
+	test_must_fail git grep --quiet "only in the index" HEAD
+'
+
+test_expect_success 'grep does not report i-t-a with -L --cached' '
+	echo "intend to add this" >intend-to-add &&
+	git add -N intend-to-add &&
+	test_when_finished "git rm -f intend-to-add" &&
+	git ls-files | grep -v "^intend-to-add\$" >expected &&
+	git grep -L --cached "nonexistent_string" >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'grep does not report i-t-a and assume unchanged with -L' '
+	echo "intend to add this" >intend-to-add-assume-unchanged &&
+	git add -N intend-to-add-assume-unchanged &&
+	test_when_finished "git rm -f intend-to-add-assume-unchanged" &&
+	git update-index --assume-unchanged intend-to-add-assume-unchanged &&
+	git ls-files | grep -v "^intend-to-add-assume-unchanged\$" >expected &&
+	git grep -L "nonexistent_string" >actual &&
+	test_cmp expected actual
+'
+
 test_done