diff --git a/arch/um/sys-ppc/Makefile b/arch/um/sys-ppc/Makefile
index b8bc844fd2c4..20d363bd7004 100644
--- a/arch/um/sys-ppc/Makefile
+++ b/arch/um/sys-ppc/Makefile
@@ -6,7 +6,7 @@ OBJ = built-in.o
 OBJS = ptrace.o sigcontext.o checksum.o miscthings.o misc.o \
 	ptrace_user.o sysrq.o
 
-EXTRA_AFLAGS := -DCONFIG_PPC32 -I. -I$(srctree)/arch/ppc/kernel
+asflags-y := -DCONFIG_PPC32 -I. -I$(srctree)/arch/ppc/kernel
 
 all: $(OBJ)
 
@@ -15,10 +15,10 @@ $(OBJ): $(OBJS)
 	$(LD) $(LINKFLAGS) --start-group $^ --end-group -o $@
 
 ptrace_user.o: ptrace_user.c
-	$(CC) -D__KERNEL__ $(USER_CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+	$(CC) -D__KERNEL__ $(USER_CFLAGS) $(ccflags-y) -c -o $@ $<
 
 sigcontext.o: sigcontext.c
-	$(CC) $(USER_CFLAGS) $(EXTRA_CFLAGS) -c -o $@ $<
+	$(CC) $(USER_CFLAGS) $(ccflags-y) -c -o $@ $<
 
 checksum.S:
 	rm -f $@
@@ -53,13 +53,13 @@ ppc_defs.h: mk_defs.c ppc_defs.head \
 checksum.o: checksum.S
 	rm -f asm
 	ln -s $(srctree)/include/asm-ppc asm
-	$(CC) $(EXTRA_AFLAGS) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
+	$(CC) $(asflags-y) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
 	rm -f asm
 
 misc.o: misc.S ppc_defs.h
 	rm -f asm
 	ln -s $(srctree)/include/asm-ppc asm
-	$(CC) $(EXTRA_AFLAGS) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
+	$(CC) $(asflags-y) $(KBUILD_AFLAGS) -D__ASSEMBLY__ -D__UM_PPC__ -c $< -o $*.o
 	rm -f asm
 
 clean-files := $(OBJS) ppc_defs.h checksum.S mk_defs.c