diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
index b183ab9c5107c9236930b3d3d9e1f2c7dd27b302..dfa5f729f774d6607f6e417bb5ca379430b96257 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -13,7 +13,7 @@
 # If you really need to reference something from prom_init.o add
 # it to the list below:
 
-grep "^CONFIG_KASAN=y$" .config >/dev/null
+grep "^CONFIG_KASAN=y$" ${KCONFIG_CONFIG} >/dev/null
 if [ $? -eq 0 ]
 then
 	MEM_FUNCS="__memcpy __memset"