diff --git a/cpu/cortexm_common/Makefile.features b/cpu/cortexm_common/Makefile.features
index 65e73500bb..baa25ee296 100644
--- a/cpu/cortexm_common/Makefile.features
+++ b/cpu/cortexm_common/Makefile.features
@@ -36,3 +36,5 @@ endif
 ifneq (,$(filter armv7m armv8m,$(CPU_ARCH)))
   FEATURES_PROVIDED += no_idle_thread
 endif
+
+KCONFIG_ADD_CONFIG += $(RIOTCPU)/cortexm_common/cortexm_common.config
diff --git a/cpu/cortexm_common/cortexm_common.config b/cpu/cortexm_common/cortexm_common.config
new file mode 100644
index 0000000000..991dda3839
--- /dev/null
+++ b/cpu/cortexm_common/cortexm_common.config
@@ -0,0 +1,5 @@
+# all cortex MCU's use newlib as libc
+CONFIG_MOD_NEWLIB=y
+
+# use the nano-specs of Newlib when available
+CONFIG_MOD_NEWLIB_NANO=y
diff --git a/cpu/sam0_common/Makefile.features b/cpu/sam0_common/Makefile.features
index 636b00a912..1ce1c11662 100644
--- a/cpu/sam0_common/Makefile.features
+++ b/cpu/sam0_common/Makefile.features
@@ -15,6 +15,8 @@ FEATURES_PROVIDED += periph_wdt periph_wdt_cb periph_wdt_warning_period
 FEATURES_CONFLICT += periph_rtc:periph_rtt
 FEATURES_CONFLICT_MSG += "The RTC and RTT map to the same hardware peripheral."
 
+KCONFIG_ADD_CONFIG += $(RIOTCPU)/cortexm_common/cortexm_common.config
+
 -include $(RIOTCPU)/cortexm_common/Makefile.features
 
 # add sam0 configurations after including cortexm_common so sam0 takes precendence