diff --git a/tests/xtimer_now32_overflow/Makefile b/tests/xtimer_now32_overflow/Makefile
index cd4ba65a17..574e1cb066 100644
--- a/tests/xtimer_now32_overflow/Makefile
+++ b/tests/xtimer_now32_overflow/Makefile
@@ -14,6 +14,7 @@ BOARD_BLACKLIST += \
                    pinetime \
                    ruuvitag \
                    stm32f429i-disco \
+                   stm32f4discovery \
                    thingy52 \
                    waspmote-pro  \
                    weact-f401cc \
diff --git a/tests/xtimer_now64_continuity/Makefile b/tests/xtimer_now64_continuity/Makefile
index a792249fde..0f47d95485 100644
--- a/tests/xtimer_now64_continuity/Makefile
+++ b/tests/xtimer_now64_continuity/Makefile
@@ -15,6 +15,7 @@ BOARD_BLACKLIST += \
                    pinetime \
                    ruuvitag \
                    stm32f429i-disco \
+                   stm32f4discovery \
                    thingy52 \
                    waspmote-pro  \
                    weact-f401cc \