diff --git a/plugins/psgi/psgi_loader.c b/plugins/psgi/psgi_loader.c
index 997bad90..2684cc52 100644
--- a/plugins/psgi/psgi_loader.c
+++ b/plugins/psgi/psgi_loader.c
@@ -237,8 +237,7 @@ PerlInterpreter *uwsgi_perl_new_interpreter(void) {
                 return NULL;
         }
 
-        dTHXa(pi);
-        PERL_SET_CONTEXT(pi);
+	PERL_SET_CONTEXT(pi);
 
         PL_perl_destruct_level = 2;
         PL_origalen = 1;
@@ -249,10 +248,6 @@ PerlInterpreter *uwsgi_perl_new_interpreter(void) {
 	return pi;
 }
 
-void uwsgi_perl_set_context(PerlInterpreter *interpreter) {
-	dTHXa(interpreter);
-        PERL_SET_CONTEXT(interpreter);
-}
 
 int init_psgi_app(struct wsgi_request *wsgi_req, char *app, uint16_t app_len, PerlInterpreter **interpreters) {
 
@@ -335,7 +330,7 @@ int init_psgi_app(struct wsgi_request *wsgi_req, char *app, uint16_t app_len, Pe
 			}
 		}
 
-		uwsgi_perl_set_context(interpreters[i]);
+		PERL_SET_CONTEXT(interpreters[i]);
 
 		uperl.tmp_current_i = i;
 
@@ -358,7 +353,7 @@ int init_psgi_app(struct wsgi_request *wsgi_req, char *app, uint16_t app_len, Pe
 			exit(1);
 		}
 
-		uwsgi_perl_set_context(interpreters[0]);
+		PERL_SET_CONTEXT(interpreters[0]);
 	}
 
 	free(buf);
@@ -399,7 +394,6 @@ int init_psgi_app(struct wsgi_request *wsgi_req, char *app, uint16_t app_len, Pe
 
 	// restore context if required
 	if (interpreters != uperl.main) {
-		dTHXa(uperl.main[0]);
 		PERL_SET_CONTEXT(uperl.main[0]);
 	}
 
@@ -415,7 +409,6 @@ clear:
 		free(interpreters);
 	}
 
-	dTHXa(uperl.main[0]);
 	PERL_SET_CONTEXT(uperl.main[0]);
        	return -1; 
 }
diff --git a/plugins/psgi/psgi_plugin.c b/plugins/psgi/psgi_plugin.c
index 98e54c67..355bce8d 100644
--- a/plugins/psgi/psgi_plugin.c
+++ b/plugins/psgi/psgi_plugin.c
@@ -22,8 +22,7 @@ extern struct http_status_codes hsc[];
 SV *uwsgi_perl_obj_new(char *class, size_t class_len) {
 
 	SV *newobj;
-	// set current context ?
-	dTHX;
+
 	dSP;
 
 	ENTER;
@@ -50,10 +49,8 @@ SV *uwsgi_perl_call_stream(SV *func) {
 	SV *ret = NULL;
 	struct wsgi_request *wsgi_req = current_wsgi_req();
 	struct uwsgi_app *wi = &uwsgi_apps[wsgi_req->app_id];
-        // set current context ?
-        dTHX;
-        dSP;
 
+        dSP;
         ENTER;
         SAVETMPS;
         PUSHMARK(SP);
@@ -80,8 +77,7 @@ SV *uwsgi_perl_call_stream(SV *func) {
 int uwsgi_perl_obj_can(SV *obj, char *method, size_t len) {
 
 	int ret;
-        // set current context ? needed for threading
-        dTHX;
+
         dSP;
 
         ENTER;
@@ -109,7 +105,6 @@ SV *uwsgi_perl_obj_call(SV *obj, char *method) {
 
         SV *ret = NULL;
 
-	dTHX;
         dSP;
 
         ENTER;
@@ -143,7 +138,6 @@ AV *psgi_call(struct wsgi_request *wsgi_req, SV *psgi_func, SV *env) {
 
 	AV *ret = NULL;
 
-	dTHX;
         dSP;
 
         ENTER;
@@ -292,6 +286,13 @@ int uwsgi_perl_init(){
 	uperl.embedding[1] = "-e";
 	uperl.embedding[2] = "0";
 
+#ifndef USE_ITHREADS
+	if (uwsgi.threads > 1) {
+		uwsgi_log("your Perl environment does not support threads\n");
+		exit(1);
+	} 
+#endif
+
 	if (setenv("PLACK_ENV", "uwsgi", 0)) {
 		uwsgi_error("setenv()");
 	}
@@ -320,6 +321,8 @@ int uwsgi_perl_init(){
                 }
 	}
 
+	PERL_SET_CONTEXT(uperl.main[0]);
+
 	// filling http status codes
 	for (http_sc = hsc; http_sc->message != NULL; http_sc++) {
 		http_sc->message_size = strlen(http_sc->message);
@@ -377,7 +380,6 @@ int uwsgi_perl_request(struct wsgi_request *wsgi_req) {
 	wi->requests++;
 
 	if (((PerlInterpreter **)wi->interpreter)[wsgi_req->async_id] != uperl.main[wsgi_req->async_id]) {
-		dTHXa(((PerlInterpreter **)wi->interpreter)[wsgi_req->async_id]);
 		PERL_SET_CONTEXT(((PerlInterpreter **)wi->interpreter)[wsgi_req->async_id]);
 	}
 
@@ -427,7 +429,6 @@ clear:
 
 	// restore main interpreter if needed
 	if (((PerlInterpreter **)wi->interpreter)[wsgi_req->async_id] != uperl.main[wsgi_req->async_id]) {
-		dTHXa(uperl.main[wsgi_req->async_id]);
 		PERL_SET_CONTEXT(uperl.main[wsgi_req->async_id]);
 	}
 
@@ -481,17 +482,21 @@ void uwsgi_perl_post_fork() {
 
 int uwsgi_perl_mount_app(char *mountpoint, char *app, int regexp) {
 
-        uwsgi.wsgi_req->appid = mountpoint;
-        uwsgi.wsgi_req->appid_len = strlen(mountpoint);
+	if (uwsgi_endswith(app, ".pl") || uwsgi_endswith(app, ".psgi")) {
+        	uwsgi.wsgi_req->appid = mountpoint;
+        	uwsgi.wsgi_req->appid_len = strlen(mountpoint);
 
-        return init_psgi_app(uwsgi.wsgi_req, app, strlen(app), NULL);
+        	return init_psgi_app(uwsgi.wsgi_req, app, strlen(app), NULL);
+	}
+	return -1;
 
 }
 
 void uwsgi_perl_init_thread(int core_id) {
 
-	dTHXa(uperl.main[core_id]);
+#ifdef USE_ITHREADS
         PERL_SET_CONTEXT(uperl.main[core_id]);
+#endif
 }
 
 struct uwsgi_plugin psgi_plugin = {
diff --git a/plugins/python/python_plugin.c b/plugins/python/python_plugin.c
index b800820f..e2e7ff71 100644
--- a/plugins/python/python_plugin.c
+++ b/plugins/python/python_plugin.c
@@ -812,12 +812,14 @@ int uwsgi_python_magic(char *mountpoint, char *lazy) {
 int uwsgi_python_mount_app(char *mountpoint, char *app, int regexp) {
 
 	int id;
-	uwsgi.wsgi_req->appid = mountpoint;
-	uwsgi.wsgi_req->appid_len = strlen(mountpoint);
-	if (uwsgi.single_interpreter) {
-		id = init_uwsgi_app(LOADER_MOUNT, app, uwsgi.wsgi_req, up.main_thread, PYTHON_APP_TYPE_WSGI);
-	}
-	id = init_uwsgi_app(LOADER_MOUNT, app, uwsgi.wsgi_req, NULL, PYTHON_APP_TYPE_WSGI);
+
+	if (strchr(app, ':') || uwsgi_endswith(app, ".py") || uwsgi_endswith(app, ".wsgi")) {
+		uwsgi.wsgi_req->appid = mountpoint;
+		uwsgi.wsgi_req->appid_len = strlen(mountpoint);
+		if (uwsgi.single_interpreter) {
+			id = init_uwsgi_app(LOADER_MOUNT, app, uwsgi.wsgi_req, up.main_thread, PYTHON_APP_TYPE_WSGI);
+		}
+		id = init_uwsgi_app(LOADER_MOUNT, app, uwsgi.wsgi_req, NULL, PYTHON_APP_TYPE_WSGI);
 
 #ifdef UWSGI_PCRE
 	int i;
@@ -833,7 +835,9 @@ int uwsgi_python_mount_app(char *mountpoint, char *app, int regexp) {
 	}
 #endif
 
-	return id;
+		return id;
+	}
+	return -1;
 
 }
 
diff --git a/protocol.c b/protocol.c
index 668f9665..ec102154 100644
--- a/protocol.c
+++ b/protocol.c
@@ -564,14 +564,19 @@ int uwsgi_parse_vars(struct wsgi_request *wsgi_req) {
 
 	/* set an HTTP 500 status as default */
 	wsgi_req->status = 500;
-	
+
+	// skip if already parsed
+	if (wsgi_req->parsed) return 0;
+
 	// has the protocol already parsed the request ?
 	if (wsgi_req->uri_len > 0) {
+		wsgi_req->parsed = 1;
 		i = uwsgi_simple_parse_vars(wsgi_req, ptrbuf, bufferend);
 		if (i == 0) goto next;
 		return i;
 	}
 
+	wsgi_req->parsed = 1;
 	wsgi_req->path_info_pos = -1;
 
 	while (ptrbuf < bufferend) {
diff --git a/uwsgi.h b/uwsgi.h
index 3a10b072..5e1bde70 100644
--- a/uwsgi.h
+++ b/uwsgi.h
@@ -739,6 +739,7 @@ struct wsgi_request {
 
 	int app_id;
 	int dynamic;
+	int parsed;
 
 	char *appid;
 	uint16_t appid_len;