diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index d8fde02ea3..482ef263c2 100755
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -5595,7 +5595,7 @@ RELEASE_GCC5_AARCH64_DLINK_FLAGS = DEF(GCC5_AARCH64_DLINK_FLAGS) -flto -Os -L$(W
 DEFINE CLANG35_ARM_TARGET        = -target arm-linux-gnueabihf
 DEFINE CLANG35_AARCH64_TARGET    = -target aarch64-linux-gnu
 
-DEFINE CLANG35_WARNING_OVERRIDES = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body
+DEFINE CLANG35_WARNING_OVERRIDES = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unknown-warning-option
 DEFINE CLANG35_ARM_CC_FLAGS      = DEF(GCC_ARM_CC_FLAGS) DEF(CLANG35_ARM_TARGET) DEF(CLANG35_WARNING_OVERRIDES)
 DEFINE CLANG35_AARCH64_CC_FLAGS  = DEF(GCC_AARCH64_CC_FLAGS) DEF(CLANG35_AARCH64_TARGET) -mcmodel=small DEF(CLANG35_WARNING_OVERRIDES)
 
@@ -5664,8 +5664,8 @@ DEFINE CLANG38_X64_PREFIX           = ENV(CLANG38_BIN)
 DEFINE CLANG38_IA32_TARGET          = -target i686-pc-linux-gnu
 DEFINE CLANG38_X64_TARGET           = -target x86_64-pc-linux-gnu
 
-DEFINE CLANG38_WARNING_OVERRIDES    = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs
-DEFINE CLANG38_ALL_CC_FLAGS         = DEF(GCC44_ALL_CC_FLAGS) DEF(CLANG38_WARNING_OVERRIDES) -fno-stack-protector -mms-bitfields -Wno-address -Wno-shift-negative-value -Wno-unknown-pragmas -Wno-incompatible-library-redeclaration -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -msoft-float -mno-implicit-float  -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang -funsigned-char -fno-ms-extensions -Wno-null-dereference -Wno-unknown-warning-option
+DEFINE CLANG38_WARNING_OVERRIDES    = -Wno-parentheses-equality -Wno-tautological-compare -Wno-tautological-constant-out-of-range-compare -Wno-empty-body -Wno-unused-const-variable -Wno-varargs -Wno-unknown-warning-option
+DEFINE CLANG38_ALL_CC_FLAGS         = DEF(GCC44_ALL_CC_FLAGS) DEF(CLANG38_WARNING_OVERRIDES) -fno-stack-protector -mms-bitfields -Wno-address -Wno-shift-negative-value -Wno-unknown-pragmas -Wno-incompatible-library-redeclaration -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -msoft-float -mno-implicit-float  -ftrap-function=undefined_behavior_has_been_optimized_away_by_clang -funsigned-char -fno-ms-extensions -Wno-null-dereference
 
 ###########################
 # CLANG38 IA32 definitions