diff --git a/.travis/before_install.sh b/.travis/before_install.sh
index f6ab0ba..1a41217 100755
--- a/.travis/before_install.sh
+++ b/.travis/before_install.sh
@@ -2,6 +2,6 @@
 
 if brew --version 2>/dev/null 2>&1; then
     # FIXME: no ncurses formula for now; also add ruby
-    brew install slang doxygen 
+    brew install slang doxygen
 fi
 
diff --git a/Makefile.am b/Makefile.am
index 29bd893..585ce7f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 SUBDIRS = kernel caca src examples tools \
           cxx caca-sharp python ruby java doc
 DIST_SUBDIRS = $(SUBDIRS) win32
diff --git a/build/autotools/common.am b/build/autotools/common.am
new file mode 100644
index 0000000..4ef6181
--- /dev/null
+++ b/build/autotools/common.am
@@ -0,0 +1,6 @@
+
+AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I$(top_builddir)/caca
+
+echo-topdir: ; echo $(top_srcdir)
+echo-sources: ; echo $(SOURCES) $(EXTRA_CHECKS)
+
diff --git a/caca-sharp/Makefile.am b/caca-sharp/Makefile.am
index 970ccb3..bb64d65 100644
--- a/caca-sharp/Makefile.am
+++ b/caca-sharp/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 # We need to install the .config file ourselves because of a gacutil
 # bug (https://bugzilla.novell.com/show_bug.cgi?id=363341)
 monodir = $(libdir)/mono/caca-sharp-0.0
diff --git a/caca/Makefile.am b/caca/Makefile.am
index 69fde09..96a5b2d 100644
--- a/caca/Makefile.am
+++ b/caca/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 SUBDIRS = . t
 
 EXTRA_DIST = caca.pc.in \
@@ -6,7 +8,7 @@ EXTRA_DIST = caca.pc.in \
              libcaca.vcxproj libcaca.def
 DISTCLEANFILES = caca.pc
 
-AM_CPPFLAGS = -I$(top_srcdir) -DPLUGINDIR=\"$(plugindir)\"
+AM_CPPFLAGS += -DPLUGINDIR=\"$(plugindir)\"
 
 pkgconfig_DATA = caca.pc
 pkgconfigdir = $(libdir)/pkgconfig
@@ -108,5 +110,3 @@ if USE_COCOA
 driver_source += driver/cocoa.m
 endif
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/caca/t/Makefile.am b/caca/t/Makefile.am
index 63443fb..ea78dac 100644
--- a/caca/t/Makefile.am
+++ b/caca/t/Makefile.am
@@ -1,5 +1,5 @@
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I..
+include $(top_srcdir)/build/autotools/common.am
 
 if USE_CPPUNIT
 cppunit_tests = caca-test
diff --git a/caca/t/check-copyright b/caca/t/check-copyright
index 9c4b58c..2cf25d6 100755
--- a/caca/t/check-copyright
+++ b/caca/t/check-copyright
@@ -1,27 +1,30 @@
 #!/bin/sh
 
+export MAKEFLAGS=""
+top_srcdir="$(make -s echo-topdir)"
+
 #
 # Check that the copyright information is valid
 #
 nfails=0
 nfiles=0
-for dir in $(make -s echo-dirs -C ..); do
-  if [ ! -d "../$dir" ]; then continue; fi
-  for x in $(make -s echo-sources -C ../$dir); do
+for dir in $(make -s echo-dirs -C "${top_srcdir}"); do
+  if [ ! -d "${top_srcdir}/${dir}" ]; then continue; fi
+  for x in $(make -s echo-sources -C "${top_srcdir}/${dir}"); do
     case "$x" in
       *.c|*.cpp|*.h|*.m|*.php|*.cs|*.java|.py|.pl)
         nfiles=$(($nfiles + 1)) ;;
       *)
         continue ;;
     esac
-    if ! grep 'Copyright *([cC])' "../$dir/$x" >/dev/null 2>&1; then
-      echo "error: $dir/$x lacks proper copyright information"
+    if ! grep 'Copyright *([cC])' "${top_srcdir}/${dir}/$x" >/dev/null 2>&1; then
+      echo "error: ${dir}/$x lacks proper copyright information"
       nfails=$(($nfails + 1))
-    elif [ -d ../.git ]; then
-      Y="$(git log "../$dir/$x" | head -n 3 | sed -ne 's/^Date.* \([0-9][0-9][0-9][0-9]\) .*/\1/p')"
+    elif [ -d ../../.git ]; then
+      Y="$(git log "${top_srcdir}/${dir}/$x" | head -n 3 | sed -ne 's/^Date.* \([0-9][0-9][0-9][0-9]\) .*/\1/p')"
       if [ "$Y" != "" ]; then
-        if ! grep "$Y.*@" "../$dir/$x" >/dev/null 2>&1; then
-          echo "error: $dir/$x last modified in $Y, which is not in copyright"
+        if ! grep "$Y.*@" "${top_srcdir}/${dir}/$x" >/dev/null 2>&1; then
+          echo "error: ${dir}/$x last modified in $Y, which is not in copyright"
           nfails=$(($nfails + 1))
         fi
       fi
diff --git a/caca/t/check-doxygen b/caca/t/check-doxygen
index d9ccd75..69dcd2d 100755
--- a/caca/t/check-doxygen
+++ b/caca/t/check-doxygen
@@ -1,11 +1,14 @@
 #!/bin/sh
 
+export MAKEFLAGS=""
+top_srcdir="$(make -s echo-topdir 2>/dev/null)"
+
 #
 # Check for Doxygen warnings
 #
-nfiles="$(grep -c "Parsing file" < ../../doc/doxygen.log)"
-if nfails="$(grep -c Warning: ../../doc/doxygen.log 2>/dev/null)"; then
-  grep Warning: ../../doc/doxygen.log | sed 's/\(.\{75\}\)...*/\1 .../'
+nfiles="$(grep -c "Parsing file" < "${top_srcdir}/doc/doxygen.log")"
+if nfails="$(grep -c Warning: "${top_srcdir}/doc/doxygen.log" 2>/dev/null)"; then
+  grep Warning: "${top_srcdir}/doc/doxygen.log" | sed 's/\(.\{75\}\)...*/\1 .../'
 fi
 
 echo "$nfiles files, $nfails visible errors in documentation"
diff --git a/caca/t/check-source b/caca/t/check-source
index 1466225..2c9612c 100755
--- a/caca/t/check-source
+++ b/caca/t/check-source
@@ -1,27 +1,30 @@
 #!/bin/sh
 
+export MAKEFLAGS=""
+top_srcdir="$(make -s echo-topdir)"
+
 #
 # Check that we have no tabs or trailing spaces in the source code
 #
 nfails=0
 nfiles=0
 nlines=0
-for dir in $(make -s echo-dirs -C ..); do
-  if [ ! -d "../$dir" ]; then continue; fi
-  for x in $(make -s echo-sources -C ../$dir); do
+for dir in $(make -s echo-dirs -C "${top_srcdir}"); do
+  if [ ! -d "${top_srcdir}/${dir}" ]; then continue; fi
+  for x in $(make -s echo-sources -C "${top_srcdir}/${dir}"); do
     case "$x" in
       *.c|*.cpp|*.h|*.m|*.php|*.cs|*.java|*.py|*.pl)
         nfiles=$(($nfiles + 1));
-        nlines=$(($nlines + `grep -c . "../$dir/$x"`)) ;;
+        nlines=$(($nlines + `grep -c . "${top_srcdir}/${dir}/$x"`)) ;;
       *)
         continue ;;
     esac
-    if grep '[[:space:]]$' "../$dir/$x" >/dev/null 2>&1; then
-      echo "error: $dir/$x contains trailing spaces"
+    if grep '[[:space:]]$' "${top_srcdir}/${dir}/$x" >/dev/null 2>&1; then
+      echo "error: ${dir}/$x contains trailing spaces"
       nfails=$(($nfails + 1))
     fi
-    if grep '	' "../$dir/$x" >/dev/null 2>&1; then
-      echo "error: $dir/$x contains tabs"
+    if grep '	' "${top_srcdir}/${dir}/$x" >/dev/null 2>&1; then
+      echo "error: ${dir}/$x contains tabs"
       nfails=$(($nfails + 1))
     fi
   done
diff --git a/caca/t/check-win32 b/caca/t/check-win32
index 27c041b..1cc7639 100755
--- a/caca/t/check-win32
+++ b/caca/t/check-win32
@@ -1,13 +1,14 @@
 #!/bin/sh
 
-ret=0
+export MAKEFLAGS=""
+top_srcdir="$(make -s echo-topdir)"
 
 #
 # Check that the Win32 config.h is in sync with config.h.in
 #
 
-config_h_in=$(dirname "$0")/../config.h.in
-win32_config_h=$(dirname "$0")/../win32/config.h
+config_h_in="${top_srcdir}/config.h.in"
+win32_config_h="${top_srcdir}/win32/config.h"
 
 nfails=0
 ntokens=0
diff --git a/cxx/Makefile.am b/cxx/Makefile.am
index af19a6f..2a2def7 100644
--- a/cxx/Makefile.am
+++ b/cxx/Makefile.am
@@ -1,5 +1,5 @@
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I../caca
+include $(top_srcdir)/build/autotools/common.am
 
 EXTRA_DIST = libcaca++.vcxproj libcaca++.def test-cxx.vcxproj
 if USE_CXX
@@ -31,5 +31,3 @@ uninstall-local:
 	rm -f $(DESTDIR)$(pkgconfigdir)/cucul++.pc
 	rmdir $(DESTDIR)$(pkgconfigdir) 2>/dev/null || true
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 5598ce3..0b58c76 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 EXTRA_DIST = doxygen.cfg.in doxygen.css footer.html header.html \
              $(man_MANS) $(doxygen_DOX)
 CLEANFILES = doxygen.log stamp-latex stamp-doxygen
diff --git a/examples/Makefile.am b/examples/Makefile.am
index 2aff95c..0e8122e 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -1,5 +1,5 @@
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I$(top_builddir)/caca
+include $(top_srcdir)/build/autotools/common.am
 
 noinst_PROGRAMS = trifiller blit canvas colors conio $(conio_snake) demo demo0 dithering driver event export figfont font font2tga frames fullwidth gamma hsv input spritedit swallow text transform truecolor unicode import mouse
 
@@ -96,5 +96,3 @@ import_LDADD = ../caca/libcaca.la
 mouse_SOURCES = mouse.c
 mouse_LDADD = ../caca/libcaca.la
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/java/Makefile.am b/java/Makefile.am
index 9213794..aa399c1 100644
--- a/java/Makefile.am
+++ b/java/Makefile.am
@@ -1,9 +1,9 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 jnidir = $(libdir)/jni
 libcaca_javadir = $(datadir)/java
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I../caca
-
 java_jar = libjava.jar
 
 if USE_JAVA
diff --git a/kernel/Makefile.am b/kernel/Makefile.am
index 18fd635..87d295a 100644
--- a/kernel/Makefile.am
+++ b/kernel/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 EXTRA_DIST = bootsect.S
 
 lib_LTLIBRARIES = $(libkernel_la)
@@ -13,11 +15,8 @@ libkernel_la_SOURCES = \
 	multiboot.h \
 	$(NULL)
 libkernel_la_LDFLAGS = -no-undefined
-AM_CPPFLAGS = -I$(top_srcdir)
 
 clean: clean-local
 clean-local:
 	rm -f bootsect.bin kern.bin kernel.map
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/python/Makefile.am b/python/Makefile.am
index 634f904..ae88229 100644
--- a/python/Makefile.am
+++ b/python/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 if USE_PYTHON
 cacadir = $(pythondir)/caca
 caca_PYTHON = \
@@ -8,6 +10,7 @@ caca_PYTHON = \
     caca/display.py \
     caca/dither.py \
     caca/font.py
+EXTRA_CHECKS = $(caca_PYTHON)
 endif
 
 EXTRA_DIST = \
@@ -24,5 +27,3 @@ EXTRA_DIST = \
     examples/gol.py \
     examples/text.py
 
-echo-sources: ; echo $(caca_PYTHON)
-
diff --git a/ruby/Makefile.am b/ruby/Makefile.am
index 680418e..0c5f8a0 100644
--- a/ruby/Makefile.am
+++ b/ruby/Makefile.am
@@ -1,4 +1,6 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 rubylibdir = $(RUBY_SITEARCHDIR)
 rubysitedir = $(RUBY_SITELIBDIR)
 
@@ -38,5 +40,3 @@ EXTRA_DIST = ruby.dox \
              README \
              $(NULL)
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/src/Makefile.am b/src/Makefile.am
index 4fb5a94..5f0b22f 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,9 +1,10 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 pkgdata_DATA = caca.txt
 
 EXTRA_DIST = caca.txt cacademo.vcxproj cacafire.vcxproj cacaview.vcxproj
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I../caca \
-              -DLIBCACA=1 -DX_DISPLAY_MISSING=1
+AM_CPPFLAGS += -DLIBCACA=1 -DX_DISPLAY_MISSING=1
 
 bin_PROGRAMS = cacademo cacafire cacaplay cacaview img2txt cacaclock $(fcntl_programs)
 noinst_PROGRAMS = cacadraw
@@ -44,5 +45,3 @@ else
 fcntl_programs =
 endif
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/tools/Makefile.am b/tools/Makefile.am
index 569e481..5090e5b 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -1,6 +1,5 @@
 
-AM_CPPFLAGS = -I$(top_srcdir) -I$(top_srcdir)/caca -I../caca \
-              -I$(top_srcdir)/caca
+include $(top_srcdir)/build/autotools/common.am
 
 noinst_PROGRAMS = optipal sortchars $(pango_programs)
 
@@ -20,5 +19,3 @@ else
 pango_programs =
 endif
 
-echo-sources: ; echo $(SOURCES)
-
diff --git a/win32/Makefile.am b/win32/Makefile.am
index 00cfe3b..15d62c7 100644
--- a/win32/Makefile.am
+++ b/win32/Makefile.am
@@ -1,3 +1,5 @@
 
+include $(top_srcdir)/build/autotools/common.am
+
 EXTRA_DIST = config.h