diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 95813df908012..d628724087c60 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -24,6 +24,14 @@ ifeq ($(HAS_BIARCH),y)
 ifeq ($(CROSS32_COMPILE),)
 CROSS32CC	:= $(CC) -m32
 KBUILD_ARFLAGS	+= --target=elf32-powerpc
+ifdef CONFIG_PPC32
+# These options will be overridden by any -mcpu option that the CPU
+# or platform code sets later on the command line, but they are needed
+# to set a sane 32-bit cpu target for the 64-bit cross compiler which
+# may default to the wrong ISA.
+KBUILD_CFLAGS		+= -mcpu=powerpc
+KBUILD_AFLAGS		+= -mcpu=powerpc
+endif
 endif
 endif