diff --git a/arch/sim/src/sim/README.txt b/arch/sim/src/sim/README.txt
deleted file mode 100644
index fc4429b01c4..00000000000
--- a/arch/sim/src/sim/README.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-This is just a placeholder to assure that this fake "chip" directory exits.
-The simulation, of course, has no chips.
-
diff --git a/arch/sim/src/up_internal.h b/arch/sim/src/sim/up_internal.h
similarity index 100%
rename from arch/sim/src/up_internal.h
rename to arch/sim/src/sim/up_internal.h
diff --git a/boards/Board.mk b/boards/Board.mk
index ce57cfb8d78..2bcdcbae3bc 100644
--- a/boards/Board.mk
+++ b/boards/Board.mk
@@ -65,10 +65,8 @@ endif
 else
 ifeq ($(WINTOOL),y)
   CFLAGS += -I "${shell cygpath -w $(SCHEDSRCDIR)}"
-ifeq ($(CONFIG_ARCH_SIM),y)
-  CFLAGS += -I "${shell cygpath -w $(ARCHSRCDIR)}"
-else
   CFLAGS += -I "${shell cygpath -w $(ARCHSRCDIR)$(DELIM)chip}"
+ifneq ($(CONFIG_ARCH_SIM),y)
   CFLAGS += -I "${shell cygpath -w $(ARCHSRCDIR)$(DELIM)common}"
 ifneq ($(ARCH_FAMILY),)
   CFLAGS += -I "${shell cygpath -w $(ARCHSRCDIR)$(DELIM)$(ARCH_FAMILY)}"
@@ -76,10 +74,8 @@ endif
 endif
 else
   CFLAGS += -I$(SCHEDSRCDIR)
-ifeq ($(CONFIG_ARCH_SIM),y)
-  CFLAGS += -I$(ARCHSRCDIR)
-else
   CFLAGS += -I$(ARCHSRCDIR)$(DELIM)chip
+ifneq ($(CONFIG_ARCH_SIM),y)
   CFLAGS += -I$(ARCHSRCDIR)$(DELIM)common
 ifneq ($(ARCH_FAMILY),)
   CFLAGS += -I$(ARCHSRCDIR)$(DELIM)$(ARCH_FAMILY)