diff --git a/drivers/bmx280/include/bmx280_internals.h b/drivers/bmx280/include/bmx280_internals.h
index 839d978c97..a6ad851f95 100644
--- a/drivers/bmx280/include/bmx280_internals.h
+++ b/drivers/bmx280/include/bmx280_internals.h
@@ -113,7 +113,7 @@ extern "C" {
  * @{
  */
 #define CALIB_T_P_BASE                  (BMX280_DIG_T1_LSB_REG)
-#define CALIB_T_P_LEN                   (17U)
+#define CALIB_T_P_LEN                   (32U) /* might be larger than needed */
 #define OFFSET_T_P(x)                   (x - CALIB_T_P_BASE)
 #if defined(MODULE_BME280_SPI) || defined(MODULE_BME280_I2C)
 #define CALIB_H_BASE                    (BME280_DIG_H2_LSB_REG)
diff --git a/pkg/openthread/Makefile b/pkg/openthread/Makefile
index 64788075a1..e9d7cd9e44 100644
--- a/pkg/openthread/Makefile
+++ b/pkg/openthread/Makefile
@@ -27,6 +27,7 @@ $(info $$OPENTHREAD_ARGS is [${OPENTHREAD_ARGS}])
 
 OPENTHREAD_COMMON_FLAGS = -fdata-sections -ffunction-sections -Os
 OPENTHREAD_COMMON_FLAGS += -Wno-implicit-fallthrough -Wno-unused-parameter
+OPENTHREAD_CXXFLAGS += -Wno-class-memaccess
 
 all:
 	cd $(PKG_BUILDDIR) && PREFIX="/" ./bootstrap
@@ -35,7 +36,8 @@ all:
 		STRIP="$(STRIP)" \
 		CPPFLAGS="$(OPENTHREAD_COMMON_FLAGS) $(CFLAGS_CPU) -D$(CONFIG_FILE)" \
 		CFLAGS="$(OPENTHREAD_COMMON_FLAGS) $(CFLAGS_CPU) " \
-		CXXFLAGS="$(OPENTHREAD_COMMON_FLAGS) $(CFLAGS_CPU) -fno-exceptions -fno-rtti " \
+		CXXFLAGS="$(OPENTHREAD_COMMON_FLAGS) $(OPENTHREAD_CXXFLAGS) \
+		          $(CFLAGS_CPU) -fno-exceptions -fno-rtti " \
 		LDFLAGS="$(OPENTHREAD_COMMON_FLAGS) $(CFLAGS_CPU) -nostartfiles -specs=nano.specs \
 		-specs=nosys.specs -Wl,--gc-sections -Wl,-Map=map.map " \
 		./configure --disable-docs --host=$(TARGET_ARCH) --target=$(TARGET_ARCH) \
diff --git a/tests/unittests/Makefile b/tests/unittests/Makefile
index d1a1d93ddd..c7987d3693 100644
--- a/tests/unittests/Makefile
+++ b/tests/unittests/Makefile
@@ -1,6 +1,9 @@
 DEVELHELP ?= 0
 include ../Makefile.tests_common
 
+# temporarily disable building, see #13456.
+BOARD_BLACKLIST := saml10-xpro saml11-xpro
+
 USEMODULE += embunit
 
 ifeq (, $(filter tests-%, $(MAKECMDGOALS)))