diff --git a/orch.lua b/orch.lua
index a1da216..7275764 100644
--- a/orch.lua
+++ b/orch.lua
@@ -398,8 +398,8 @@ execute = function(func, freshctx)
 	end
 end
 
-local function include_file(file)
-	local f = assert(impl.open(file))
+local function include_file(file, alter_path)
+	local f = assert(impl.open(file, alter_path))
 	local chunk = f:read("*l")	-- * for compatibility with Lua 5.2...
 
 	if not chunk then
@@ -713,10 +713,15 @@ function orch_env.write(str)
 	return true
 end
 
+-- Valid config options:
+--   * alter_path: boolean, add script's directory to $PATH (default: false)
+--   * command: argv table to pass to spawn
 function orch.run_script(scriptfile, config)
 	local done
 
-	include_file(scriptfile)
+	-- Note that the orch(1) driver will setup alter_path == true; scripts
+	-- importing orch.lua are expected to be more explicit.
+	include_file(scriptfile, config and config.alter_path)
 	--match_ctx_stack:dump()
 
 	if config and config.command then
diff --git a/orch_interp.c b/orch_interp.c
index 3a0f1a1..77c810c 100644
--- a/orch_interp.c
+++ b/orch_interp.c
@@ -102,19 +102,21 @@ orch_interp(const char *scriptf, const char *orch_invoke_path,
 	if (luaL_dofile(L, orch_interp_script(orch_invoke_path)) != LUA_OK) {
 		status = orch_interp_error(L);
 	} else {
-		int nargs = 1;
-
 		/*
 		 * orch table is now at the top of stack, fetch run_script()
 		 * and call it.  run_script(scriptf[, config])
 		 */
 		lua_getfield(L, -1, "run_script");
 		lua_pushstring(L, scriptf);
-		if (argc > 0) {
-			/* config */
-			lua_createtable(L, 0, 1);
-			nargs++;
 
+		/* config */
+		lua_createtable(L, 0, 1);
+
+		/* config.alter_path */
+		lua_pushboolean(L, 1);
+		lua_setfield(L, -2, "alter_path");
+
+		if (argc > 0) {
 			/* config.command */
 			lua_createtable(L, argc, 0);
 			for (int i = 0; i < argc; i++) {
@@ -125,7 +127,7 @@ orch_interp(const char *scriptf, const char *orch_invoke_path,
 			lua_setfield(L, -2, "command");
 		}
 
-		if (lua_pcall(L, nargs, 1, 0) == LUA_OK)
+		if (lua_pcall(L, 2, 1, 0) == LUA_OK)
 			status = lua_toboolean(L, -1) ? 0 : 1;
 		else
 			status = orch_interp_error(L);
diff --git a/orch_lua.c b/orch_lua.c
index 657af1d..2ff30be 100644
--- a/orch_lua.c
+++ b/orch_lua.c
@@ -76,7 +76,7 @@ orchlua_close(lua_State *L)
 }
 
 static int
-orchlua_open_init(const char *filename, const char **script)
+orchlua_open_init(const char *filename, const char **script, bool alter_path)
 {
 
 	assert(!orchlua_cfg.initialized);
@@ -106,8 +106,8 @@ orchlua_open_init(const char *filename, const char **script)
 		if (*script == NULL)
 			return (ENOMEM);
 
-		/* XXX Should be configurable */
-		orchlua_add_execpath(scriptroot);
+		if (alter_path)
+			orchlua_add_execpath(scriptroot);
 
 		orchlua_cfg.dirfd = open(scriptroot,
 		    O_DIRECTORY | O_PATH | O_CLOEXEC);
@@ -125,16 +125,19 @@ orchlua_open(lua_State *L)
 	luaL_Stream *p;
 	const char *filename, *script;
 	int fd, rvals;
+	bool alter_path;
 
 	rvals = 1;
 	filename = luaL_checkstring(L, 1);
+	alter_path = lua_toboolean(L, 2);
 	script = NULL;
 
 	/* First open() sets up the sandbox state. */
 	if (!orchlua_cfg.initialized) {
 		int error;
 
-		if ((error = orchlua_open_init(filename, &script)) != 0) {
+		error = orchlua_open_init(filename, &script, alter_path);
+		if (error != 0) {
 			luaL_pushfail(L);
 			lua_pushstring(L, strerror(error));
 			return (true);