diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index cb4b66e29d..33c955f912 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -419,6 +419,7 @@ while read name path pretty; do
 		(
 			git init $name-$type &&
 			cd $name-$type &&
+			git config core.protectNTFS false &&
 			echo content >file &&
 			git add file &&
 			git commit -m base &&
diff --git a/t/t7415-submodule-names.sh b/t/t7415-submodule-names.sh
index e1cd0a3545..7c65e7a35c 100755
--- a/t/t7415-submodule-names.sh
+++ b/t/t7415-submodule-names.sh
@@ -89,16 +89,18 @@ test_expect_success MINGW 'prevent git~1 squatting on Windows' '
 			git hash-object -w --stdin)" &&
 		rev="$(git rev-parse --verify HEAD)" &&
 		hash="$(echo x | git hash-object -w --stdin)" &&
-		git update-index --add \
+		git -c core.protectNTFS=false update-index --add \
 			--cacheinfo 100644,$modules,.gitmodules \
 			--cacheinfo 160000,$rev,c \
 			--cacheinfo 160000,$rev,d\\a \
 			--cacheinfo 100644,$hash,d./a/x \
 			--cacheinfo 100644,$hash,d./a/..git &&
 		test_tick &&
-		git commit -m "module"
+		git -c core.protectNTFS=false commit -m "module" &&
+		test_must_fail git show HEAD: 2>err &&
+		test_i18ngrep backslash err
 	) &&
-	test_must_fail git \
+	test_must_fail git -c core.protectNTFS=false \
 		clone --recurse-submodules squatting squatting-clone 2>err &&
 	test_i18ngrep "directory not empty" err &&
 	! grep gitdir squatting-clone/d/a/git~2
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index 866ddf6058..e6062071e6 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -421,6 +421,7 @@ test_expect_success 'directory becomes symlink'        '
 
 test_expect_success 'fast-export quotes pathnames' '
 	git init crazy-paths &&
+	test_config -C crazy-paths core.protectNTFS false &&
 	(cd crazy-paths &&
 	 blob=$(echo foo | git hash-object -w --stdin) &&
 	 git update-index --add \
diff --git a/tree-walk.c b/tree-walk.c
index d459feda23..54ff959d7f 100644
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -41,6 +41,12 @@ static int decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned l
 		strbuf_addstr(err, _("empty filename in tree entry"));
 		return -1;
 	}
+#ifdef GIT_WINDOWS_NATIVE
+	if (protect_ntfs && strchr(path, '\\')) {
+		strbuf_addf(err, _("filename in tree entry contains backslash: '%s'"), path);
+		return -1;
+	}
+#endif
 	len = strlen(path) + 1;
 
 	/* Initialize the descriptor entry */