diff --git a/arch/um/Kconfig b/arch/um/Kconfig
index 127310c..27a9741c 100644
--- a/arch/um/Kconfig
+++ b/arch/um/Kconfig
@@ -23,7 +23,13 @@
 	default y
 
 config NO_IOMEM
-	def_bool y
+	bool
+	default y if !TEST
+
+config HAS_IOMEM
+	bool "Turns on fake IOMEM support for KUnit"
+	depends on TEST
+	select MOCK_IOMEM
 
 config ISA
 	bool
diff --git a/test/Kconfig b/test/Kconfig
index ff89367..1b6d4be 100644
--- a/test/Kconfig
+++ b/test/Kconfig
@@ -6,6 +6,7 @@
 
 config TEST
 	bool "Enable support for unit tests (KUnit)"
+	select HAS_IOMEM
 	help
 	  Enables support for kernel unit tests (KUnit), a lightweight unit
 	  testing and mocking framework for the Linux kernel. These tests are