diff --git a/Makefile b/Makefile
index 80dac02..4c6c5e3 100644
--- a/Makefile
+++ b/Makefile
@@ -1385,9 +1385,13 @@
 endif #ifeq ($(mixed-targets),1)
 
 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).
 checkstack:
 	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
-	$(PERL) $(src)/scripts/checkstack.pl $(ARCH)
+	$(PERL) $(src)/scripts/checkstack.pl $(SUBARCH)
 
 kernelrelease:
 	$(if $(wildcard include/config/kernel.release), $(Q)echo $(KERNELRELEASE), \