Index: kernel/Makefile
===================================================================
--- kernel/Makefile	(revision bdca26a0f1af74aa02df60e75d1e9a51266872ef)
+++ kernel/Makefile	(revision bebd154be4d1118b08a23ce3b56a8613c8841cff)
@@ -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) \