diff --git a/platform/cc2530dk/Makefile.cc2530dk b/platform/cc2530dk/Makefile.cc2530dk
index cae4911b5..2ef71e6f3 100644
--- a/platform/cc2530dk/Makefile.cc2530dk
+++ b/platform/cc2530dk/Makefile.cc2530dk
@@ -20,7 +20,6 @@ CONTIKI_SOURCEFILES += $(CONTIKI_TARGET_SOURCEFILES)
 CLEAN += *.cc2530dk
 
 ifeq ($(UIP_CONF_IPV6),1)
-  CFLAGS += -DUIP_CONF_IPV6=1
   CONTIKI_TARGET_SOURCEFILES += viztool.c
 endif
 
diff --git a/platform/cc2538dk/Makefile.cc2538dk b/platform/cc2538dk/Makefile.cc2538dk
index 2ca46af7e..b350c2fc2 100644
--- a/platform/cc2538dk/Makefile.cc2538dk
+++ b/platform/cc2538dk/Makefile.cc2538dk
@@ -22,11 +22,6 @@ ifndef SMALL
   SMALL = 1
 endif
 
-### If the prject's Makefile specified IPv6, the pre-processor needs to know
-ifeq ($(UIP_CONF_IPV6),1)
-  CFLAGS += -DUIP_CONF_IPV6=1
-endif
-
 ### Define the CPU directory
 CONTIKI_CPU=$(CONTIKI)/cpu/cc2538
 include $(CONTIKI_CPU)/Makefile.cc2538
diff --git a/platform/sensinode/Makefile.sensinode b/platform/sensinode/Makefile.sensinode
index 743a51349..d37dafdd8 100644
--- a/platform/sensinode/Makefile.sensinode
+++ b/platform/sensinode/Makefile.sensinode
@@ -47,7 +47,6 @@ CONTIKI_SOURCEFILES += $(CONTIKI_TARGET_SOURCEFILES)
 CLEAN += *.sensinode
 
 ifeq ($(UIP_CONF_IPV6),1)
-  CFLAGS += -DUIP_CONF_IPV6=1
   ifeq ($(OFFSET_FIRMWARE),1)
     CFLAGS += -DDISCO_ENABLED=1
     CONTIKI_TARGET_SOURCEFILES += disco.c