diff --git a/Makefile.include b/Makefile.include
index 7cd2c30512..3dd322e60b 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -217,9 +217,6 @@ ifeq (1,$(TEST_KCONFIG))
   SHOULD_RUN_KCONFIG = 1
 endif
 
-# Include Kconfig functionalities
-include $(RIOTMAKE)/kconfig.mk
-
 ifeq ($(OS),Darwin)
   OPEN   := open
 else
@@ -366,6 +363,9 @@ include $(RIOTBASE)/Makefile.features
 include $(RIOTMAKE)/pseudomodules.inc.mk
 include $(RIOTMAKE)/defaultmodules.inc.mk
 
+# Include Kconfig functionalities
+include $(RIOTMAKE)/kconfig.mk
+
 # For testing, use TEST_KCONFIG as a switch between Makefile.dep and Kconfig
 ifeq (1,$(TEST_KCONFIG))
   $(info === [ATTENTION] Testing Kconfig dependency modelling ===)
diff --git a/makefiles/kconfig.mk b/makefiles/kconfig.mk
index 4c9b1c89f4..25b9040ac2 100644
--- a/makefiles/kconfig.mk
+++ b/makefiles/kconfig.mk
@@ -50,6 +50,13 @@ KCONFIG_OUT_DEP = $(KCONFIG_OUT_CONFIG).d
 
 # Add configurations to merge, in ascendent priority (i.e. a file overrides the
 # previous ones).
+ifeq (1, $(TEST_KCONFIG))
+  # KCONFIG_ADD_CONFIG holds a list of .config files that are merged for the
+  # initial configuration. This allows to split configurations in common files
+  # and share them among boards or cpus.
+  MERGE_SOURCES += $(KCONFIG_ADD_CONFIG)
+endif
+
 MERGE_SOURCES += $(wildcard $(KCONFIG_APP_CONFIG))
 MERGE_SOURCES += $(wildcard $(KCONFIG_USER_CONFIG))
 
diff --git a/makefiles/vars.inc.mk b/makefiles/vars.inc.mk
index 82c4386b25..f7fe9b101e 100644
--- a/makefiles/vars.inc.mk
+++ b/makefiles/vars.inc.mk
@@ -118,3 +118,4 @@ export LAZYSPONGE_FLAGS      # Parameters supplied to LAZYSPONGE.
 export AFL_FLAGS             # Additional command-line flags passed to afl during fuzzing.
 
 # LOG_LEVEL                  # Logging level as integer (NONE: 0, ERROR: 1, WARNING: 2, INFO: 3, DEBUG: 4, default: 3)
+# KCONFIG_ADD_CONFIG         # List of .config files to be merged used by Boards and CPUs. See kconfig.mk