diff --git a/pkg/jerryscript/Makefile.include b/pkg/jerryscript/Makefile.include
index fdf28101d4781e6dbdc1f304e58265add61f3d3b..2c4e51777bd477ae3a8d79f7dbc722aee2dee9de 100644
--- a/pkg/jerryscript/Makefile.include
+++ b/pkg/jerryscript/Makefile.include
@@ -1,2 +1,9 @@
 INCLUDES += -I$(PKGDIRBASE)/jerryscript/jerry-core/include
 INCLUDES += -I$(PKGDIRBASE)/jerryscript/jerry-ext/include
+
+ifneq (,$(filter cortex-m%,$(CPU_ARCH)))
+  # jerryscript package package is not using system includes right now, so
+  # many newlib hearders (not even stdio.h) is found
+  # Fixed in #9821 (so remove when merged)
+  TOOLCHAINS_BLACKLIST += llvm
+endif
diff --git a/pkg/micro-ecc/Makefile.include b/pkg/micro-ecc/Makefile.include
index 1bb685e1b82dac790e622ca42dceff60bc74d5b1..a40d330c1d17ce1f08e4e8034659445e323d960f 100644
--- a/pkg/micro-ecc/Makefile.include
+++ b/pkg/micro-ecc/Makefile.include
@@ -1 +1,7 @@
 INCLUDES += -I$(PKGDIRBASE)/micro-ecc
+
+ifneq (,$(filter cortex-m0%,$(CPU_ARCH)))
+  # LLVM/clang can't handle the inline assembler instructions on M0 in this
+  # package
+  TOOLCHAINS_BLACKLIST += llvm
+endif
diff --git a/pkg/nordic_softdevice_ble/Makefile.include b/pkg/nordic_softdevice_ble/Makefile.include
index 70a6563e3ebaa2dc03134ed13ab304625cb67539..a06b35192af6b56de809b332a2cbcd3cdb68e006 100644
--- a/pkg/nordic_softdevice_ble/Makefile.include
+++ b/pkg/nordic_softdevice_ble/Makefile.include
@@ -31,3 +31,6 @@ DIRS += \
 		$(NORDIC_SRCS)/components/softdevice/common/softdevice_handler \
 		$(NORDIC_SRCS)/components/ble/common \
 		$(NORDIC_SRCS)/components/iot/ble_ipsp
+
+# LLVM ARM assembler has massive problems digesting this
+TOOLCHAINS_BLACKLIST += llvm
diff --git a/pkg/openthread/Makefile.include b/pkg/openthread/Makefile.include
index 7fd2ba782f06f1a15c31707c23f67e1347ac6d5f..fdb7a72bd31eab9725c363bb6ca44e5a1a7f8972 100644
--- a/pkg/openthread/Makefile.include
+++ b/pkg/openthread/Makefile.include
@@ -8,3 +8,9 @@ ifneq (,$(filter openthread_contrib,$(USEMODULE)))
   DIRS += $(OPENTHREAD_DIR)/contrib
   DIRS += $(OPENTHREAD_DIR)/contrib/netdev
 endif
+
+ifneq (,$(filter cortex-m0% cortex-m3%,$(CPU_ARCH)))
+  # There are problem with unused `-mcpu...` arguments in clang and with
+  # ranlib + LLVM/clang in this package with Cortex-M0 and M3
+  TOOLCHAINS_BLACKLIST += llvm
+endif
diff --git a/pkg/qDSA/Makefile.include b/pkg/qDSA/Makefile.include
index d7ac128477fd75228cf4fab61d04554f2ccaa017..6d399ef6c297c139d95dac92f5b6f6cc14005087 100644
--- a/pkg/qDSA/Makefile.include
+++ b/pkg/qDSA/Makefile.include
@@ -11,3 +11,9 @@ endif
 export QDSA_IMPL
 
 INCLUDES += -I$(PKGDIRBASE)/qDSA/$(QDSA_IMPL)
+
+ifeq (cortex-m0plus,$(CPU_ARCH))
+  # There are problems with the LLVM assembler and the Cortex-M0+ instruction
+  # set with this package
+  TOOLCHAINS_BLACKLIST += llvm
+endif