diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index cc22408..ba41421 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -11,6 +11,10 @@
 obj-perf := $(abspath $(obj-perf))/
 endif
 
+$(shell echo -n > .config-detected)
+detected     = $(shell echo "$(1)=y"       >> .config-detected)
+detected_var = $(shell echo "$(1)=$($(1))" >> .config-detected)
+
 LIB_INCLUDE := $(srctree)/tools/lib/
 CFLAGS := $(EXTRA_CFLAGS) $(EXTRA_WARNINGS)