diff --git a/.gitignore b/.gitignore
index d0d84b9854..f072889f0d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,6 +10,7 @@ apps/namedapp/namedapp_proto.h
 Make.dep
 *.o
 *.a
+*.d
 *~
 *.dSYM
 Images/*.bin
diff --git a/apps/controllib/Makefile b/apps/controllib/Makefile
index 99cf910690..6749b805fa 100644
--- a/apps/controllib/Makefile
+++ b/apps/controllib/Makefile
@@ -43,11 +43,4 @@ CXXSRCS		 = block/Block.cpp \
 		   blocks.cpp \
 		   fixedwing.cpp
 
-CXXHDRS		 = block/Block.hpp \
-		   block/BlockParam.hpp \
-		   block/UOrbPublication.hpp \
-		   block/UOrbSubscription.hpp \
-		   blocks.hpp \
-		   fixedwing.hpp
-
 include $(APPDIR)/mk/app.mk
diff --git a/apps/mathlib/Makefile b/apps/mathlib/Makefile
index e5fab1e354..7eebd6ae0b 100644
--- a/apps/mathlib/Makefile
+++ b/apps/mathlib/Makefile
@@ -31,8 +31,6 @@
 #
 ############################################################################
 
-include $(TOPDIR)/.config
-
 #
 # Math library
 #
@@ -44,27 +42,21 @@ CXXSRCS		 = math/test/test.cpp \
 		   math/Dcm.cpp \
 		   math/Matrix.cpp
 
-CXXHDRS		 = math/test/test.hpp \
-		   math/Vector.hpp \
-		   math/Vector3.hpp \
-		   math/EulerAngles.hpp \
-		   math/Quaternion.hpp \
-		   math/Dcm.hpp \
-		   math/Matrix.hpp
+#
+# In order to include .config we first have to save off the
+# current makefile name, since app.mk needs it.
+#
+APP_MAKEFILE	:= $(lastword $(MAKEFILE_LIST))
+-include $(TOPDIR)/.config
 
-# XXX this really should be a CONFIG_* test
 ifeq ($(CONFIG_ARCH_CORTEXM4)$(CONFIG_ARCH_FPU),yy)
 INCLUDES	+= math/arm
 CXXSRCS		+= math/arm/Vector.cpp \
 		   math/arm/Matrix.cpp
-CXXHDRS		+= math/arm/Vector.hpp \
-		   math/arm/Matrix.hpp
 else
 INCLUDES	+= math/generic
 CXXSRCS		+= math/generic/Vector.cpp \
 		   math/generic/Matrix.cpp
-CXXHDRS		+= math/generic/Vector.hpp \
-		   math/generic/Matrix.hpp
 endif
 
 include $(APPDIR)/mk/app.mk
diff --git a/apps/mk/app.mk b/apps/mk/app.mk
index 1d8b0e44c1..fa4a12cab6 100644
--- a/apps/mk/app.mk
+++ b/apps/mk/app.mk
@@ -81,7 +81,9 @@
 # Work out who included us so we can report decent errors
 #
 THIS_MAKEFILE	:= $(lastword $(MAKEFILE_LIST))
-PARENT_MAKEFILE	:= $(lastword $(filter-out $(THIS_MAKEFILE),$(MAKEFILE_LIST)))
+ifeq ($(APP_MAKEFILE),)
+APP_MAKEFILE	:= $(lastword $(filter-out $(THIS_MAKEFILE),$(MAKEFILE_LIST)))
+endif
 
 ############################################################################
 # Get configuration
@@ -93,7 +95,7 @@ include $(APPDIR)/Make.defs
 ############################################################################
 # Sanity-check the information we've been given and set any defaults
 #
-SRCDIR		?= $(dir $(PARENT_MAKEFILE))
+SRCDIR		?= $(dir $(APP_MAKEFILE))
 PRIORITY	?= SCHED_PRIORITY_DEFAULT
 STACKSIZE	?= CONFIG_PTHREAD_STACK_DEFAULT
 
@@ -112,14 +114,14 @@ endif
 
 # there has to be a source file
 ifeq ($(ASRCS)$(CSRCS)$(CXXSRCS),)
-$(error $(realpath $(PARENT_MAKEFILE)): at least one of ASRCS, CSRCS or CXXSRCS must be set)
+$(error $(realpath $(APP_MAKEFILE)): at least one of ASRCS, CSRCS or CXXSRCS must be set)
 endif
 
 # check that C++ is configured if we have C++ source files and we are building
 ifneq ($(CXXSRCS),)
 ifneq ($(CONFIG_HAVE_CXX),y)
 ifeq ($(MAKECMDGOALS),build)
-$(error $(realpath $(PARENT_MAKEFILE)): cannot set CXXSRCS if CONFIG_HAVE_CXX not set in configuration)
+$(error $(realpath $(APP_MAKEFILE)): cannot set CXXSRCS if CONFIG_HAVE_CXX not set in configuration)
 endif
 endif
 endif
@@ -153,6 +155,11 @@ COBJS		 = $(patsubst %.c,%.o,$(CSRCS))
 CXXOBJS		 = $(patsubst %.cpp,%.o,$(CXXSRCS))
 OBJS		 = $(AOBJS) $(COBJS) $(CXXOBJS)
 
+# Automatic depdendency generation
+DEPS		 = $(OBJS:$(OBJEXT)=.d)
+CFLAGS		+= -MD
+CXXFLAGS	+= -MD
+
 # The prelinked object that we are ultimately going to build
 ifneq ($(APPNAME),)
 PRELINKOBJ	 = $(APPNAME).pre.o
@@ -160,7 +167,7 @@ else
 PRELINKOBJ	 = $(LIBNAME).pre.o
 endif
 
-# The archive that the object file will be placed in
+# The archive the prelinked object will be linked into
 # XXX does WINTOOL ever get set?
 ifeq ($(WINTOOL),y)
   INCDIROPT	= -w
@@ -186,11 +193,8 @@ all:		.built
 #
 # Source dependencies
 #
-depend:		.depend
-.depend:	$(MAKEFILE_LIST) $(SRCS)
-	@$(MKDEP) --dep-path . $(CC) -- $(CFLAGS) -- $(CSRCS) $(CHDRS) >Make.dep
-	@$(MKDEP) --dep-path . $(CXX) -- $(CXXFLAGS) -- $(CXXSRCS) $(CXXHDRS) >>Make.dep
-	@touch $@
+depend:
+	@exit 0
 
 ifneq ($(APPNAME),)
 #
@@ -202,6 +206,7 @@ context:	.context
 	@touch $@
 else
 context:
+	@exit 0
 endif
 
 #
@@ -210,23 +215,23 @@ endif
 $(PRELINKOBJ):	$(OBJS)
 	$(call PRELINK, $@, $(OBJS))
 
-$(AOBJS): %.o : %.S
+$(AOBJS): %.o : %.S $(MAKEFILE_LIST)
 	$(call ASSEMBLE, $<, $@)
 
-$(COBJS): %.o : %.c
+$(COBJS): %.o : %.c $(MAKEFILE_LIST)
 	$(call COMPILE, $<, $@)
 
-$(CXXOBJS): %.o : %.cpp
+$(CXXOBJS): %.o : %.cpp $(MAKEFILE_LIST)
 	$(call COMPILEXX, $<, $@)
 
 #
 # Tidying up
 #
 clean:
-	@rm -f $(OBJS) $(PRELINKOBJ) Make.dep .built
+	@rm -f $(OBJS) $(DEPS) $(PRELINKOBJ) .built
 	$(call CLEAN)
 
 distclean:	clean
 	@rm -f Make.dep .depend
 
--include Make.dep
+-include $(DEPS)