diff --git a/winsup/w32api/ChangeLog b/winsup/w32api/ChangeLog
index f57ab30fc..d4f0e5554 100644
--- a/winsup/w32api/ChangeLog
+++ b/winsup/w32api/ChangeLog
@@ -1,3 +1,17 @@
+2012-01-15  Keith Marshall  <keithmarshall@users.sf.net>
+
+	More makefile code refactoring; fix top_srcdir references.
+
+	* Makefile.comm.in (EXTRA_INCLUDES): Add definitions from...
+	* lib/Makefile.in (EXTRA_INCLUDES): ...here; factor out common code.
+	(top_srcdir): Use this throughout, in place of ${srcdir}/../
+
+	* lib/ddk/Makefile.in lib/directx/Makefile.in (EXTRA_INCLUDES):
+	Factor out; use corrected definitions from Makefile.comm.in
+	(top_srcdir): Use throughout, in place of ${srcdir}/../../
+	(INCLUDES): Adjust incorrect references to ${srcdir}/../include;
+	should be ${top_srcdir}/include
+
 2012-01-15  Keith Marshall  <keithmarshall@users.sf.net>
 
 	Update and correct makefile rebuilding rules.
diff --git a/winsup/w32api/Makefile.comm.in b/winsup/w32api/Makefile.comm.in
index 9a1fcf5d0..f1fa70c18 100644
--- a/winsup/w32api/Makefile.comm.in
+++ b/winsup/w32api/Makefile.comm.in
@@ -43,6 +43,24 @@ WINDRES = @WINDRES@
 RANLIB = @RANLIB@
 AR = @AR@
 
+# Depending on if we build as part of winsup or mingw we need to
+# add additional include paths in order to get the correct headers
+# from the C library.
+#
+BUILDENV = @BUILDENV@
+
+ifeq ($(BUILDENV), cygwin)
+  # winsup/include
+  # winsup/../newlib/libc/include
+  # winsup/../newlib/libc/sys/cygwin
+  EXTRA_INCLUDES = -I ${top_srcdir}/../include \
+    -I ${top_srcdir}/../../newlib/libc/include \
+    -I ${top_srcdir}/../../newlib/libc/sys/cygwin
+endif
+ifeq ($(BUILDENV), mingw)
+  EXTRA_INCLUDES = -I ${top_srcdir}/../mingw/include
+endif
+
 # In spite of its general unsuitability for use on MS-Windows hosts,
 # Cygwin is able to, and likes to support the $(DESTDIR) capability;
 # provide a graceful rejection mechanism, for any (non-Cygwin) cases
diff --git a/winsup/w32api/lib/Makefile.in b/winsup/w32api/lib/Makefile.in
index df8727ac0..d496c0910 100644
--- a/winsup/w32api/lib/Makefile.in
+++ b/winsup/w32api/lib/Makefile.in
@@ -19,29 +19,13 @@ VPATH = @srcdir@
 
 include ${top_builddir}/Makefile.comm
 
-# Depending on if we build as part of winsup or mingw we need to
-# add additional include paths in order to get the correct headers
-# from the C library.
-#
-BUILDENV = @BUILDENV@
-
-ifeq ($(BUILDENV), cygwin)
-# winsup/include
-# winsup/../newlib/libc/include
-# winsup/../newlib/libc/sys/cygwin
-EXTRA_INCLUDES = -I${srcdir}/../../include -I${srcdir}/../../../newlib/libc/include -I${srcdir}/../../../newlib/libc/sys/cygwin
-endif
-ifeq ($(BUILDENV), mingw)
-EXTRA_INCLUDES = -I${srcdir}/../../mingw/include
-endif
-
-INCLUDES = -I${srcdir}/../include $(EXTRA_INCLUDES)
+INCLUDES = -I ${top_srcdir}/include $(EXTRA_INCLUDES)
 
 # Headers
 #
-HEADERS = $(notdir $(wildcard ${srcdir}/../include/*.h))
-GL_HEADERS = $(notdir $(wildcard ${srcdir}/../include/GL/*.h))
-GDIPLUS_HEADERS = $(notdir $(wildcard ${srcdir}/../include/gdiplus/*.h))
+HEADERS = $(notdir $(wildcard ${top_srcdir}/include/*.h))
+GL_HEADERS = $(notdir $(wildcard ${top_srcdir}/include/GL/*.h))
+GDIPLUS_HEADERS = $(notdir $(wildcard ${top_srcdir}/include/gdiplus/*.h))
 
 # Libraries
 #
@@ -152,15 +136,15 @@ install-libraries: all $(need-DESTDIR-compatibility)
 install-headers: $(need-DESTDIR-compatibility)
 	$(mkinstalldirs) $(DESTDIR)${inst_includedir}
 	for file in $(HEADERS); do \
-	  $(INSTALL_DATA) ${srcdir}/../include/$$file $(DESTDIR)${inst_includedir}; \
+	  $(INSTALL_DATA) ${top_srcdir}/include/$$file $(DESTDIR)${inst_includedir}; \
 	done
 	$(mkinstalldirs) $(DESTDIR)${inst_includedir}/GL
 	for file in $(GL_HEADERS); do \
-	  $(INSTALL_DATA) ${srcdir}/../include/GL/$$file $(DESTDIR)${inst_includedir}/GL; \
+	  $(INSTALL_DATA) ${top_srcdir}/include/GL/$$file $(DESTDIR)${inst_includedir}/GL; \
 	done
 	$(mkinstalldirs) $(DESTDIR)${inst_includedir}/gdiplus
 	for file in $(GDIPLUS_HEADERS); do \
-	  $(INSTALL_DATA) ${srcdir}/../include/gdiplus/$$file $(DESTDIR)${inst_includedir}/gdiplus; \
+	  $(INSTALL_DATA) ${top_srcdir}/include/gdiplus/$$file $(DESTDIR)${inst_includedir}/gdiplus; \
 	done
 
 install-ddk: install-libraries install-headers
@@ -195,15 +179,15 @@ dist:
 	mkdir ${distdir}/include
 	chmod 755 ${distdir}/include
 	for file in $(HEADERS); do \
-	  cp -p ${srcdir}/../include/$$file ${distdir}/include; \
+	  cp -p ${top_srcdir}/include/$$file ${distdir}/include; \
 	done
 	mkdir ${distdir}/include/GL
 	for file in $(GL_HEADERS); do \
-	  cp -p ${srcdir}/../include/GL/$$file ${distdir}/include/GL; \
+	  cp -p ${top_srcdir}/include/GL/$$file ${distdir}/include/GL; \
 	done
 	mkdir ${distdir}/include/gdiplus
 	for file in $(GDIPLUS_HEADERS); do \
-	  cp -p ${srcdir}/../include/gdiplus/$$file ${distdir}/include/gdiplus; \
+	  cp -p ${top_srcdir}/include/gdiplus/$$file ${distdir}/include/gdiplus; \
 	done
 	mkdir ${distdir}/lib
 	chmod 755 ${distdir}/lib
diff --git a/winsup/w32api/lib/ddk/Makefile.in b/winsup/w32api/lib/ddk/Makefile.in
index 7879cdedc..d6813b6ce 100644
--- a/winsup/w32api/lib/ddk/Makefile.in
+++ b/winsup/w32api/lib/ddk/Makefile.in
@@ -16,28 +16,11 @@ top_builddir = @top_builddir@
 VPATH = @srcdir@
 
 include ${top_builddir}/Makefile.comm
-
-# Depending on if we build as part of winsup or mingw we need to
-# add additional include paths in order to get the correct headers
-# from the C library.
-#
-BUILDENV = @BUILDENV@
-
-ifeq ($(BUILDENV), cygwin)
-# winsup/include
-# winsup/../newlib/libc/include
-# winsup/../newlib/libc/sys/cygwin
-EXTRA_INCLUDES = -I${srcdir}/../../include -I${srcdir}/../../../newlib/libc/include -I${srcdir}/../../../newlib/libc/sys/cygwin
-endif
-ifeq ($(BUILDENV), mingw)
-EXTRA_INCLUDES = -I${srcdir}/../../mingw/include
-endif
-
-INCLUDES = -I${srcdir}/../include $(EXTRA_INCLUDES)
+INCLUDES = -I ${top_srcdir}/include $(EXTRA_INCLUDES)
 
 # Headers
 #
-HEADERS = $(notdir $(wildcard ${srcdir}/../../include/ddk/*.h))
+HEADERS = $(notdir $(wildcard ${top_srcdir}/include/ddk/*.h))
 
 # Libraries
 #
@@ -91,7 +74,7 @@ ddk_includedir = ${inst_includedir}/ddk
 install-headers: $(need-DESTDIR-compatibility)
 	$(mkinstalldirs) $(DESTDIR)${ddk_includedir}
 	for file in $(HEADERS); do \
-	  $(INSTALL_DATA) ${srcdir}/../../include/ddk/$$file $(DESTDIR)${ddk_includedir}; \
+	  $(INSTALL_DATA) ${top_srcdir}/include/ddk/$$file $(DESTDIR)${ddk_includedir}; \
 	done
 
 # Uninstall headers and libraries from a target specified directory
@@ -114,7 +97,7 @@ dist:
 	mkdir ${distdir}/include/ddk
 	chmod 755 ${distdir}/include/ddk
 	for file in $(HEADERS); do \
-	  cp -p ${srcdir}/../../include/ddk/$$file ${distdir}/include/ddk; \
+	  cp -p ${top_srcdir}/include/ddk/$$file ${distdir}/include/ddk; \
 	done
 	mkdir ${distdir}/lib/ddk
 	chmod 755 ${distdir}/lib/ddk
diff --git a/winsup/w32api/lib/directx/Makefile.in b/winsup/w32api/lib/directx/Makefile.in
index c085f390f..ff2cc85a7 100644
--- a/winsup/w32api/lib/directx/Makefile.in
+++ b/winsup/w32api/lib/directx/Makefile.in
@@ -16,31 +16,12 @@ top_builddir = @top_builddir@
 VPATH = @srcdir@
 
 include ${top_builddir}/Makefile.comm
-
-# Depending on if we build as part of winsup or mingw we need to
-# add additional include paths in order to get the correct headers
-# from the C library.
-#
-BUILDENV = @BUILDENV@
-
-ifeq ($(BUILDENV), cygwin)
-  # winsup/include
-  # winsup/../newlib/libc/include
-  # winsup/../newlib/libc/sys/cygwin
-  EXTRA_INCLUDES = -I ${srcdir}/../../include \
-    -I ${srcdir}/../../../newlib/libc/include \
-    -I ${srcdir}/../../../newlib/libc/sys/cygwin
-endif
-ifeq ($(BUILDENV), mingw)
-  EXTRA_INCLUDES = -I ${srcdir}/../../mingw/include
-endif
-
-INCLUDES = -I ${srcdir}/../include -I ${srcdir}/../include/directx \
+INCLUDES = -I ${top_srcdir}/include -I ${top_srcdir}/include/directx \
   $(EXTRA_INCLUDES)
 
 # Headers
 #
-HEADERS = $(notdir $(wildcard ${srcdir}/../../include/directx/*.h))
+HEADERS = $(notdir $(wildcard ${top_srcdir}/include/directx/*.h))
 
 # Libraries
 #
@@ -70,7 +51,7 @@ all-default: $(LIBS)
 
 TEST_OPTIONS = \
   $(ALL_CFLAGS) -Wall -pedantic -Wsystem-headers \
-  -c $(srcdir)/test.c -o test.o
+  -c ${srcdir}/test.c -o test.o
 .PHONY: test
 test:
 	@echo "Testing directx..."
@@ -119,7 +100,7 @@ install-libraries: all $(need-DESTDIR-compatibility)
 install-headers: $(need-DESTDIR-compatibility)
 	$(mkinstalldirs) $(DESTDIR)${inst_includedir}
 	for file in $(HEADERS); do \
-	  $(INSTALL_DATA) ${srcdir}/../../include/directx/$$file $(DESTDIR)${inst_includedir}; \
+	  $(INSTALL_DATA) ${top_srcdir}/include/directx/$$file $(DESTDIR)${inst_includedir}; \
 	done
 
 # Uninstall headers and libraries from a target specified directory
@@ -142,7 +123,7 @@ dist:
 	mkdir ${distdir}/include/directx
 	chmod 755 ${distdir}/include/directx
 	for file in $(HEADERS); do \
-	  cp -p ${srcdir}/../../include/directx/$$file ${distdir}/include/directx; \
+	  cp -p ${top_srcdir}/include/directx/$$file ${distdir}/include/directx; \
 	done
 	mkdir ${distdir}/lib/directx
 	chmod 755 ${distdir}/lib/directx