diff --git a/Makefile b/Makefile
index 68982ba..2626de3 100644
--- a/Makefile
+++ b/Makefile
@@ -877,6 +877,9 @@
 # insure the checker run with the right endianness
 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
 
+# the checker needs the correct machine size
+CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
+
 # Default kernel image to build when no specific target is given.
 # KBUILD_IMAGE may be overruled on the command line or
 # set in the environment