diff --git a/folly/memory/test/UninitializedMemoryHacksTest.cpp b/folly/memory/test/UninitializedMemoryHacksTest.cpp
index 38e27c3..17424af 100644
--- a/folly/memory/test/UninitializedMemoryHacksTest.cpp
+++ b/folly/memory/test/UninitializedMemoryHacksTest.cpp
@@ -283,7 +283,7 @@ TEST(UninitializedMemoryHacks, simpleStringWChar) {
 }
 
 TEST(UninitializedMemoryHacks, simpleStringSChar) {
-  testSimple<std::basic_string<signed char>>();
+  testSimple<std::basic_string<char>>();
 }
 
 TEST(UninitializedMemoryHacks, simpleVectorChar) {
@@ -307,7 +307,7 @@ TEST(UninitializedMemoryHacks, randomStringWChar) {
 }
 
 TEST(UninitializedMemoryHacks, randomStringSChar) {
-  testRandom<std::basic_string<signed char>>();
+  testRandom<std::basic_string<char>>();
 }
 
 TEST(UninitializedMemoryHacks, randomVectorChar) {
@@ -323,5 +323,5 @@ TEST(UninitializedMemoryHacks, randomVectorInt) {
 }
 
 // We are deliberately putting this at the bottom to make sure it can follow use
-FOLLY_DECLARE_STRING_RESIZE_WITHOUT_INIT(signed char)
+//FOLLY_DECLARE_STRING_RESIZE_WITHOUT_INIT(char)
 FOLLY_DECLARE_VECTOR_RESIZE_WITHOUT_INIT(int)