--- a/configure.ac	2009-12-25 19:06:22.000000000 +0200
+++ b/configure.ac	2012-10-30 16:59:12.000000000 +0200
@@ -77,10 +77,12 @@
 
 AC_MSG_CHECKING([for PySignal_SetWakeupFd in Python.h])
 py_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.prefix)"`
-if test -x "$PYTHON-config"; then
-PYTHON_INCLUDES=`$PYTHON-config --includes 2>/dev/null`
-else
-PYTHON_INCLUDES="-I${py_prefix}/include/python${PYTHON_VERSION}"
+if test -z $PYTHON_INCLUDES; then
+	if test -x "$PYTHON-config"; then
+		PYTHON_INCLUDES=`$PYTHON-config --includes 2>/dev/null`
+	else
+		PYTHON_INCLUDES="-I${py_prefix}/include/python${PYTHON_VERSION}"
+	fi
 fi
 old_CPPFLAGS=$CPPFLAGS
 CPPFLAGS="-Wall -Werror $PYTHON_INCLUDES"
--- a/m4/python.m4	2009-12-18 11:03:34.000000000 +0200
+++ b/m4/python.m4	2012-10-30 17:41:19.000000000 +0200
@@ -45,6 +45,7 @@
 dnl deduce PYTHON_INCLUDES
 py_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.prefix)"`
 py_exec_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.exec_prefix)"`
+if test -z "$PYTHON_INCLUDES"; then
 if test -x "$PYTHON-config"; then
 PYTHON_INCLUDES=`$PYTHON-config --includes 2>/dev/null`
 else
@@ -53,6 +54,7 @@
   PYTHON_INCLUDES="$PYTHON_INCLUDES -I${py_exec_prefix}/include/python${PYTHON_VERSION}"
 >fi
 fi
+fi
 AC_SUBST(PYTHON_INCLUDES)
 dnl check if the headers exist:
 save_CPPFLAGS="$CPPFLAGS"
@@ -236,6 +238,7 @@
 dnl deduce PYTHON_INCLUDES
 py_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.prefix)"`
 py_exec_prefix=`$PYTHON -c "import sys; sys.stdout.write(sys.exec_prefix)"`
+if test -z "$PYTHON_INCLUDES"; then
 if test -x "$PYTHON-config"; then
 PYTHON_INCLUDES=`$PYTHON-config --includes 2>/dev/null`
 else
@@ -244,6 +247,7 @@
   PYTHON_INCLUDES="$PYTHON_INCLUDES -I${py_exec_prefix}/include/python${PYTHON_VERSION}"
 fi
 fi
+fi
 AC_SUBST(PYTHON_INCLUDES)
 dnl check if the headers exist:
 save_CPPFLAGS="$CPPFLAGS"