diff --git a/extmod/extmod.mk b/extmod/extmod.mk
index 9b1e51718e41d..3678448eb5f59 100644
--- a/extmod/extmod.mk
+++ b/extmod/extmod.mk
@@ -159,6 +159,7 @@ SRC_LIB_LIBM_DBL_SQRT_HW_C += lib/libm_dbl/thumb_vfp_sqrt.c
 
 # Too many warnings in libm_dbl, disable for now.
 $(BUILD)/lib/libm_dbl/%.o: CFLAGS += -Wno-double-promotion -Wno-float-conversion
+$(BUILD)/lib/libm/kf_rem_pio2.o: CFLAGS += -Wno-maybe-uninitialized
 
 ################################################################################
 # VFS FAT FS
diff --git a/ports/stm32/posix_helpers.c b/ports/stm32/posix_helpers.c
index b72c4ff9d6671..4cdd3dca163e2 100644
--- a/ports/stm32/posix_helpers.c
+++ b/ports/stm32/posix_helpers.c
@@ -27,6 +27,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <errno.h>
+#include <time.h>
 #include "py/mphal.h"
 #include "py/gc.h"
 
@@ -67,7 +68,3 @@ uint32_t htonl(uint32_t netlong) {
 time_t time(time_t *t) {
     return mp_hal_ticks_ms() / 1000;
 }
-
-time_t mktime(void *tm) {
-    return 0;
-}