diff --git a/Makefile b/Makefile
index 4eabaa8..f732e75 100644
--- a/Makefile
+++ b/Makefile
@@ -1390,12 +1390,18 @@
 
 PHONY += checkstack kernelrelease kernelversion
 
-# Use $(SUBARCH) here instead of $(ARCH) so that this works for UML.
-# In the UML case, $(SUBARCH) is the name of the underlying
-# architecture, while for all other arches, it is the same as $(ARCH).
+# UML needs a little special treatment here.  It wants to use the host
+# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
+# else wants $(ARCH), including people doing cross-builds, which means
+# that $(SUBARCH) doesn't work here.
+ifeq ($(ARCH), um)
+CHECKSTACK_ARCH := $(SUBARCH)
+else
+CHECKSTACK_ARCH := $(ARCH)
+endif
 checkstack:
 	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
-	$(PERL) $(src)/scripts/checkstack.pl $(SUBARCH)
+	$(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
 
 kernelrelease:
 	$(if $(wildcard include/config/kernel.release), $(Q)echo $(KERNELRELEASE), \