Filter out -pthread for cproto.
diff --git a/src/configure.in b/src/configure.in
index a18c683..567c7a2 100644
--- a/src/configure.in
+++ b/src/configure.in
@@ -764,7 +764,6 @@
 	else
 	  PYTHON_CFLAGS="-I${vi_cv_path_python_pfx}/include/python${vi_cv_var_python_version} -I${vi_cv_path_python_epfx}/include/python${vi_cv_var_python_version}"
 	fi
-	PYTHON_NOPROTO=
 	PYTHON_SRC="if_python.c"
 	dnl For Mac OSX 10.2 config.o is included in the Python library.
 	if test "x$MACOSX" = "xyes"; then
@@ -784,8 +783,6 @@
 	dnl Otherwise, when using GCC, try adding -pthread to $CFLAGS.  GCC
 	dnl will then define target-specific defines, e.g., -D_REENTRANT.
 	dnl Don't do this for Mac OSX, -pthread will generate a warning.
-	dnl Need to put -pthread in PYTHON_NOPROTO, because it cannot be used
-	dnl for cproto.
 	AC_MSG_CHECKING([if -pthread should be used])
 	threadsafe_flag=
 	thread_lib=
@@ -803,7 +800,7 @@
 	  CFLAGS="$CFLAGS $threadsafe_flag"
 	  LIBS="$LIBS $thread_lib"
 	  AC_TRY_LINK(,[ ],
-	     AC_MSG_RESULT(yes); PYTHON_NOPROTO="$threadsafe_flag",
+	     AC_MSG_RESULT(yes); PYTHON_CFLAGS="$PYTHON_CFLAGS $threadsafe_flag",
 	     AC_MSG_RESULT(no); LIBS=$libs_save_old
 	     )
 	  CFLAGS=$cflags_save
@@ -816,7 +813,7 @@
 	AC_MSG_CHECKING([if compile and link flags for Python are sane])
 	cflags_save=$CFLAGS
 	libs_save=$LIBS
-	CFLAGS="$CFLAGS $PYTHON_CFLAGS $PYTHON_NOPROTO"
+	CFLAGS="$CFLAGS $PYTHON_CFLAGS"
 	LIBS="$LIBS $PYTHON_LIBS"
 	AC_TRY_LINK(,[ ],
 	       AC_MSG_RESULT(yes); python_ok=yes,
@@ -831,7 +828,6 @@
 	  PYTHON_OBJ=
 	  PYTHON_LIBS=
 	  PYTHON_CFLAGS=
-	  PYTHON_NOPROTO=
 	fi
 
       fi
@@ -844,7 +840,6 @@
 AC_SUBST(PYTHON_LIBS)
 AC_SUBST(PYTHON_GETPATH_CFLAGS)
 AC_SUBST(PYTHON_CFLAGS)
-AC_SUBST(PYTHON_NOPROTO)
 AC_SUBST(PYTHON_SRC)
 AC_SUBST(PYTHON_OBJ)