diff --git a/pkg/tlsf/Makefile.dep b/pkg/tlsf/Makefile.dep
index f83eaa710f..3ca354f82c 100644
--- a/pkg/tlsf/Makefile.dep
+++ b/pkg/tlsf/Makefile.dep
@@ -7,3 +7,6 @@ ifneq (,$(filter tlsf-malloc,$(USEMODULE)))
     $(warning tlsf-malloc can only be used on native or on platforms using newlib)
   endif
 endif
+
+# tlsf is not compatible with 8bit and 16bit architectures
+FEATURES_REQUIRED += arch_32bit