diff --git a/Makefile.dep b/Makefile.dep
index d63dae9ed4..0d1751434a 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -676,6 +676,10 @@ ifneq (,$(filter sock_dns,$(USEMODULE)))
   USEMODULE += sock_util
 endif
 
+ifneq (,$(filter sock_util,$(USEMODULE)))
+  USEMODULE += posix
+endif
+
 ifneq (,$(filter event_%,$(USEMODULE)))
   USEMODULE += event
 endif