diff --git a/configure.in b/configure.in
index b68b5ce6fd..78bcea481c 100644
--- a/configure.in
+++ b/configure.in
@@ -124,7 +124,7 @@ dnl Initialize libtool
 AC_PROG_CC
 AM_DISABLE_STATIC
 
-if test "os_win32" = "yes"; then
+if test "$os_win32" = "yes"; then
   if test x$enable_static = xyes -o x$enable_static = x; then
     AC_MSG_WARN([Disabling static library build, must build as DLL on Windows.])
     enable_static=no