diff --git a/configure.in b/configure.in
index 774e0a8..ab7cd56 100644
--- a/configure.in
+++ b/configure.in
@@ -148,7 +148,7 @@ done
 AC_MSG_RESULT($QTDIR)
 AM_CONDITIONAL(USE_QT, test -n "$QTLIBDIR")
 if test -z "$QTLIBDIR"; then
-   AC_MSG_WARN(Could not locate QT 4.1)
+   AC_MSG_ERROR(Could not locate QT 4)
   case $host in
     *darwin*)
       LDFLAGS+=" -lproxy"