--- configure.in
+++ configure.in
@@ -20,6 +20,7 @@ AM_INIT_AUTOMAKE([1.7])
 dnl ===========================================================================
 
 # libtool shared library version
+m4_pattern_allow([^LT_(CURRENT|REVISION|AGE)$])dnl
 
 # Increment if the interface has additions, changes, removals.
 LT_CURRENT=13
@@ -56,7 +57,9 @@ AC_PATH_PROG(XARGS, xargs)
 dnl ===========================================================================
 
 AC_PROG_CC
+AC_PROG_CXX
 AC_PROG_CPP
+AM_PROG_CC_C_O
 AC_LIBTOOL_WIN32_DLL
 AC_PROG_LIBTOOL dnl required version (1.4) DON'T REMOVE!
 AC_STDC_HEADERS