diff --git a/configure.ac b/configure.ac
index 9a1ec62..7f52da6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -24,6 +24,7 @@
     if test "x$enable_win64" != "xyes"
     then
       test -n "$CC" || CC="gcc -m32"
+      test -n "$CXX"|| CXX="g++ -m32"
       test -n "$LD" || LD="ld -m elf_i386"
       test -n "$AS" || AS="as --32"
       host_cpu="i386"