diff --git a/doc/imapfilter.1 b/doc/imapfilter.1
index ff66c37..f6e3f73 100644
--- a/doc/imapfilter.1
+++ b/doc/imapfilter.1
@@ -24,7 +24,7 @@ The command line options of
 are as follows:
 .Bl -tag -width Ds
 .It Fl c Ar configfile
-Path to the configuration file.  The default is
+Path to the configuration file, or - to read from stdin.  The default is
 .Pa $HOME/.imapfilter/config.lua .
 .It Fl d Ar debugfile
 File that contains debugging information about the full communication with the
diff --git a/src/lua.c b/src/lua.c
index 795be55..e97ee1d 100644
--- a/src/lua.c
+++ b/src/lua.c
@@ -78,7 +78,7 @@ start_lua()
 		    "=<command line>") || lua_pcall(lua, 0, LUA_MULTRET, 0))
 			fatal(ERROR_CONFIG, "%s\n", lua_tostring(lua, -1));
 	} else {
-		if (luaL_loadfile(lua, opts.config))
+		if (luaL_loadfile(lua, strcmp(opts.config, "-") == 0 ? NULL : opts.config))
 			fatal(ERROR_CONFIG, "%s\n", lua_tostring(lua, -1));
 		lua_pushcfunction(lua, traceback_handler);
 		lua_insert(lua, 1);