diff --git a/tests/pkg_fff/Makefile b/tests/pkg_fff/Makefile
index b644207afa..81a603aaf0 100644
--- a/tests/pkg_fff/Makefile
+++ b/tests/pkg_fff/Makefile
@@ -5,10 +5,10 @@ FEATURES_BLACKLIST += periph_i2c
 
 include $(RIOTBASE)/Makefile.include
 
-ifneq ($(CPU_FAM),esp32)
+ifneq ($(MCU),esp32)
   # only two threads used
   CFLAGS += -DMAXTHREADS=2
 else
-  # ESP32 uses an extra thread for esp_timer
+  # ESP32x SoCs uses an extra thread for esp_timer
   CFLAGS += -DMAXTHREADS=3
 endif