diff --git a/git-filter-branch.sh b/git-filter-branch.sh
index 5777947a5d..27c9c54fbd 100755
--- a/git-filter-branch.sh
+++ b/git-filter-branch.sh
@@ -377,7 +377,7 @@ while read commit parents; do
 	fi
 
 	{
-		while read -r header_line && test -n "$header_line"
+		while IFS='' read -r header_line && test -n "$header_line"
 		do
 			# skip header lines...
 			:;
diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index 855afda80a..377c648e04 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -2,6 +2,7 @@
 
 test_description='git filter-branch'
 . ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
 
 test_expect_success 'setup' '
 	test_commit A &&
@@ -292,6 +293,19 @@ test_expect_success 'Tag name filtering strips gpg signature' '
 	test_cmp expect actual
 '
 
+test_expect_success GPG 'Filtering retains message of gpg signed commit' '
+	mkdir gpg &&
+	touch gpg/foo &&
+	git add gpg &&
+	test_tick &&
+	git commit -S -m "Adding gpg" &&
+
+	git log -1 --format="%s" > expect &&
+	git filter-branch -f --msg-filter "cat" &&
+	git log -1 --format="%s" > actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'Tag name filtering allows slashes in tag names' '
 	git tag -m tag-with-slash X/1 &&
 	git cat-file tag X/1 | sed -e s,X/1,X/2, > expect &&