:: commit 2d959e0d0266ba8dfef30bc6e5ff67bdd181f0bd

diff --git a/common/common.mk b/common/common.mk
index 44c50721..f996ad8e 100644
--- a/common/common.mk
+++ b/common/common.mk
@@ -76,8 +76,9 @@ ifeq ($(TARGET),bios)
     override CPPFLAGS_FOR_TARGET := \
         $(CPPFLAGS_FOR_TARGET) \
         -DBIOS
-    override NASMFLAGS_FOR_TARGET += \
+    override NASMFLAGS_FOR_TARGET := \
         -f elf32 \
+        $(NASMFLAGS_FOR_TARGET) \
         -DIA32_TARGET \
         -DBIOS
 endif
@@ -97,8 +98,9 @@ ifeq ($(TARGET),uefi-x86-64)
         -I ../nyu-efi/inc \
         $(CPPFLAGS_FOR_TARGET) \
         -DUEFI
-    override NASMFLAGS_FOR_TARGET += \
+    override NASMFLAGS_FOR_TARGET := \
         -f elf64 \
+        $(NASMFLAGS_FOR_TARGET) \
         -DX86_64_TARGET \
         -DUEFI
 endif
@@ -114,8 +116,9 @@ ifeq ($(TARGET),uefi-ia32)
         -I ../nyu-efi/inc \
         $(CPPFLAGS_FOR_TARGET) \
         -DUEFI
-    override NASMFLAGS_FOR_TARGET += \
+    override NASMFLAGS_FOR_TARGET := \
         -f elf32 \
+        $(NASMFLAGS_FOR_TARGET) \
         -DIA32_TARGET \
         -DUEFI
 endif
diff --git a/decompressor/decompressor.mk b/decompressor/decompressor.mk
index c8b0c787..920039ea 100644
--- a/decompressor/decompressor.mk
+++ b/decompressor/decompressor.mk
@@ -47,12 +47,13 @@ override LDFLAGS_FOR_TARGET += \
     -static \
     -T linker.ld
 
-override NASMFLAGS_FOR_TARGET += \
+override NASMFLAGS_FOR_TARGET := \
+    -f elf32 \
+    $(NASMFLAGS_FOR_TARGET) \
     -Wall \
     -w-unknown-warning \
     -w-reloc \
-    $(WERROR_FLAG) \
-    -f elf32
+    $(WERROR_FLAG)
 
 override C_FILES := $(shell find . -type f -name '*.c' | LC_ALL=C sort)
 override ASM_FILES := $(shell find . -type f -name '*.asm' | LC_ALL=C sort)