diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index 859fbe14ad..dd44de0335 100644
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -4255,8 +4255,8 @@ DEFINE GCC49_AARCH64_ASLDLINK_FLAGS  = DEF(GCC48_AARCH64_ASLDLINK_FLAGS)
 *_GCC46_ARM_RC_FLAGS             = DEF(GCC_ARM_RC_FLAGS)
 *_GCC46_ARM_VFRPP_FLAGS          = $(ARCHCC_FLAGS) $(PLATFORM_FLAGS) DEF(GCC_VFRPP_FLAGS)
 
-  DEBUG_GCC46_ARM_CC_FLAGS       = DEF(GCC46_ARM_CC_FLAGS) -O0
-RELEASE_GCC46_ARM_CC_FLAGS       = DEF(GCC46_ARM_CC_FLAGS) -Wno-unused-but-set-variable
+  DEBUG_GCC46_ARM_CC_FLAGS       = DEF(GCC46_ARM_CC_FLAGS) -D__ARM_FEATURE_UNALIGNED=0 -O0
+RELEASE_GCC46_ARM_CC_FLAGS       = DEF(GCC46_ARM_CC_FLAGS) -D__ARM_FEATURE_UNALIGNED=0 -Wno-unused-but-set-variable
 
 ####################################################################################
 #