diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
index f88f8605e1..45cfaff390 100644
--- a/BaseTools/Conf/tools_def.template
+++ b/BaseTools/Conf/tools_def.template
@@ -3961,7 +3961,7 @@ DEFINE GCC49_AARCH64_ASLDLINK_FLAGS  = DEF(GCC_ARM_AARCH64_ASLDLINK_FLAGS)
 *_UNIXGCC_IA32_CC_FLAGS             = DEF(GCC_IA32_CC_FLAGS)
 *_UNIXGCC_IA32_RC_FLAGS             = DEF(GCC_IA32_RC_FLAGS)
 *_UNIXGCC_IA32_OBJCOPY_FLAGS        =
-*_UNIXGCC_IA32_NASM_FLAGS           = -f elf32
+*_UNIXGCC_IA32_NASM_FLAGS           = -f win32
 
 ##################
 # X64 definitions
@@ -3981,7 +3981,7 @@ DEFINE GCC49_AARCH64_ASLDLINK_FLAGS  = DEF(GCC_ARM_AARCH64_ASLDLINK_FLAGS)
 *_UNIXGCC_X64_CC_FLAGS              = DEF(GCC_X64_CC_FLAGS)
 *_UNIXGCC_X64_RC_FLAGS              = DEF(GCC_X64_RC_FLAGS)
 *_UNIXGCC_X64_OBJCOPY_FLAGS         =
-*_UNIXGCC_X64_NASM_FLAGS            = -f elf64
+*_UNIXGCC_X64_NASM_FLAGS            = -f win64
 
 ##################
 # IPF definitions
@@ -4649,7 +4649,7 @@ RELEASE_GCC49_AARCH64_CC_FLAGS   = DEF(GCC49_AARCH64_CC_FLAGS) -Wno-unused-but-s
 *_CYGGCC_IA32_CC_FLAGS           = DEF(GCC_IA32_CC_FLAGS)
 *_CYGGCC_IA32_RC_FLAGS           = DEF(GCC_IA32_RC_FLAGS)
 *_CYGGCC_IA32_OBJCOPY_FLAGS      =
-*_CYGGCC_IA32_NASM_FLAGS         = -f elf32
+*_CYGGCC_IA32_NASM_FLAGS         = -f win32
 
 ##################
 # X64 definitions
@@ -4670,7 +4670,7 @@ RELEASE_GCC49_AARCH64_CC_FLAGS   = DEF(GCC49_AARCH64_CC_FLAGS) -Wno-unused-but-s
 *_CYGGCC_X64_CC_FLAGS            = DEF(GCC_X64_CC_FLAGS)
 *_CYGGCC_X64_RC_FLAGS            = DEF(GCC_X64_RC_FLAGS)
 *_CYGGCC_X64_OBJCOPY_FLAGS       =
-*_CYGGCC_X64_NASM_FLAGS          = -f elf64
+*_CYGGCC_X64_NASM_FLAGS          = -f win64
 
 ##################
 # IPF definitions