Index: kernel/Makefile
===================================================================
--- kernel/Makefile	(revision 42e91ae287bf1525ef41e4cc821ffb99f0562d68)
+++ kernel/Makefile	(revision 64b78543468fe92af33fa325a4e790bde95aa21d)
@@ -87,5 +87,5 @@
 INCLUDES_FLAGS = $(addprefix -I,$(INCLUDES))
 
-DEFS = -DKERNEL -DRELEASE=$(RELEASE) "-DCOPYRIGHT=$(COPYRIGHT)" "-DNAME=$(NAME)" -D__$(BITS)_BITS__ -D__$(ENDIANESS)__
+DEFS = -D_HELENOS_SOURCE -DKERNEL -DRELEASE=$(RELEASE) "-DCOPYRIGHT=$(COPYRIGHT)" "-DNAME=$(NAME)" -D__$(BITS)_BITS__ -D__$(ENDIANESS)__
 
 COMMON_CFLAGS = $(INCLUDES_FLAGS) -O$(OPTIMIZATION) -imacros $(CONFIG_HEADER) \