diff --git a/configure.ac b/configure.ac
index 640c4de0f..7bd9f637f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -708,7 +708,7 @@ else
       AC_MSG_CHECKING(for Python library directory)
       if test -d $PYPREFIX/libs; then
         PYLIB=$PYPREFIX/libs
-        PYLINKFILE=`ls $PYLIB/python*.lib | grep "python[[0-9]][[0-9]]\.lib"`
+        PYLINKFILE=`ls $PYLIB/python*.lib | grep "python[[0-9]][[0-9]]\+\.lib"`
         if test -r "$PYLINKFILE"; then
           PYLINK=-l`basename $PYLINKFILE | sed -e 's/\.lib$//'`
         else
@@ -864,7 +864,7 @@ else
       AC_MSG_CHECKING(for Python 3.x library directory)
       if test -d $PY3PREFIX/libs; then
         PY3LIB=$PY3PREFIX/libs
-        PY3LINKFILE=`ls $PY3LIB/python*.lib | grep "python[[0-9]][[0-9]]\.lib"`
+        PY3LINKFILE=`ls $PY3LIB/python*.lib | grep "python[[0-9]][[0-9]]\+\.lib"`
         if test -r "$PY3LINKFILE"; then
           PY3LINK=-l`basename $PY3LINKFILE | sed -e 's/\.lib$//'`
         else