diff --git a/configure.ac b/configure.ac
index 21fd01c..921bfed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -12,6 +12,7 @@ AC_CONFIG_HEADERS([libqpdf/qpdf/qpdf-config.h])
 AC_PROG_CC
 AC_PROG_CXX
 AC_HEADER_STDC
+LT_INIT([win32-dll])
 AC_PROG_LIBTOOL
 
 AC_CHECK_HEADER(zlib.h,,[MISSING_ZLIB_H=1; MISSING_ANY=1])