diff --git a/ext/pdo_oci/config.m4 b/ext/pdo_oci/config.m4
index cb2a832d977..8b768294b37 100755
--- a/ext/pdo_oci/config.m4
+++ b/ext/pdo_oci/config.m4
@@ -1,6 +1,6 @@
 dnl $Id$
 
-AC_DEFUN(AC_PDO_OCI_VERSION,[
+AC_DEFUN([AC_PDO_OCI_VERSION],[
   AC_MSG_CHECKING([Oracle version])
   if test -s "$PDO_OCI_DIR/orainst/unix.rgs"; then
     PDO_OCI_VERSION=`grep '"ocommon"' $PDO_OCI_DIR/orainst/unix.rgs | sed 's/[ ][ ]*/:/g' | cut -d: -f 6 | cut -c 2-4`
diff --git a/ext/pdo_odbc/config.m4 b/ext/pdo_odbc/config.m4
index 5e00784c1dd..f7113a9207e 100755
--- a/ext/pdo_odbc/config.m4
+++ b/ext/pdo_odbc/config.m4
@@ -2,7 +2,7 @@ dnl $Id$
 dnl config.m4 for extension pdo_odbc
 dnl vim:et:sw=2:ts=2:
 
-AC_DEFUN(PDO_ODBC_HELP_TEXT, [[
+AC_DEFUN([PDO_ODBC_HELP_TEXT], [[
  --with-pdo-odbc=flavour,dir  Add support for "flavour" ODBC drivers,
                               looking for include and lib dirs under "dir"
          
diff --git a/ext/pdo_pgsql/config.m4 b/ext/pdo_pgsql/config.m4
index a915fb0b175..5aa283c1464 100644
--- a/ext/pdo_pgsql/config.m4
+++ b/ext/pdo_pgsql/config.m4
@@ -2,7 +2,7 @@ dnl
 dnl $Id$
 dnl
 
-AC_DEFUN(PHP_PGSQL_CHECK_FUNCTIONS,[
+AC_DEFUN([PHP_PGSQL_CHECK_FUNCTIONS],[
 ])
 
 PHP_ARG_WITH(pdo-pgsql,for PostgreSQL support for PDO,
diff --git a/ext/xmlwriter/config.m4 b/ext/xmlwriter/config.m4
index 18d630482c1..a1952b38797 100644
--- a/ext/xmlwriter/config.m4
+++ b/ext/xmlwriter/config.m4
@@ -2,7 +2,7 @@ dnl
 dnl $Id$
 dnl
 
-AC_DEFUN(PHP_XMLWRITER_CHECK_VERSION,[
+AC_DEFUN([PHP_XMLWRITER_CHECK_VERSION],[
   old_CPPFLAGS=$CPPFLAGS
   CPPFLAGS=-I$XMLWRITER_DIR/include$XMLWRITER_DIR_ADD
   AC_MSG_CHECKING(for libxml version)