--- configure.ac
+++ configure.ac
@@ -64,6 +64,7 @@
 # Note: this can apparently alter CFLAGS, on a few platforms, e.g., on
 # SCO OpenServer 5 (i.e. *-*-sco3.2v5*), "-belf" is added.
 AC_PROG_LIBTOOL
+AC_PROG_CXX
 
 # Determine extension (e.g. ".exe") on executables, if any.
 AC_EXEEXT