diff --git a/include/haproxy/applet.h b/include/haproxy/applet.h
index 97b9c347b..b4c33ea26 100644
--- a/include/haproxy/applet.h
+++ b/include/haproxy/applet.h
@@ -113,6 +113,8 @@ static inline void appctx_free(struct appctx *appctx)
 /* wakes up an applet when conditions have changed */
 static inline void appctx_wakeup(struct appctx *appctx)
 {
+	ALREADY_CHECKED(appctx);
+
 	task_wakeup(appctx->t, TASK_WOKEN_OTHER);
 }
 
diff --git a/include/haproxy/conn_stream.h b/include/haproxy/conn_stream.h
index 517d6d2f6..5dc9cf265 100644
--- a/include/haproxy/conn_stream.h
+++ b/include/haproxy/conn_stream.h
@@ -93,7 +93,7 @@ static inline struct check *cs_check(const struct conn_stream *cs)
 
 static inline struct stream_interface *cs_si(const struct conn_stream *cs)
 {
-	return (cs_strm(cs) ? cs->si : NULL);
+	return cs->si;
 }
 
 static inline const char *cs_get_data_name(const struct conn_stream *cs)
diff --git a/include/haproxy/stream_interface.h b/include/haproxy/stream_interface.h
index 8119a4233..88fc16f83 100644
--- a/include/haproxy/stream_interface.h
+++ b/include/haproxy/stream_interface.h
@@ -55,13 +55,19 @@ void si_sync_send(struct stream_interface *si);
 /* returns the channel which receives data from this stream interface (input channel) */
 static inline struct channel *si_ic(struct stream_interface *si)
 {
-	return ((si->flags & SI_FL_ISBACK) ? &(cs_strm(si->cs)->res) : &(cs_strm(si->cs)->req));
+	struct stream *strm = cs_strm(si->cs);
+
+	ALREADY_CHECKED(strm);
+	return ((si->flags & SI_FL_ISBACK) ? &(strm->res) : &(strm->req));
 }
 
 /* returns the channel which feeds data to this stream interface (output channel) */
 static inline struct channel *si_oc(struct stream_interface *si)
 {
-	return ((si->flags & SI_FL_ISBACK) ? &(cs_strm(si->cs)->req) : &(cs_strm(si->cs)->res));
+	struct stream *strm = cs_strm(si->cs);
+
+	ALREADY_CHECKED(strm);
+	return ((si->flags & SI_FL_ISBACK) ? &(strm->req) : &(strm->res));
 }
 
 /* returns the buffer which receives data from this stream interface (input channel's buffer) */
@@ -79,19 +85,28 @@ static inline struct buffer *si_ob(struct stream_interface *si)
 /* returns the stream associated to a stream interface */
 static inline struct stream *si_strm(struct stream_interface *si)
 {
-	return cs_strm(si->cs);
+	struct stream *strm = cs_strm(si->cs);
+
+	ALREADY_CHECKED(strm);
+	return strm;
 }
 
 /* returns the task associated to this stream interface */
 static inline struct task *si_task(struct stream_interface *si)
 {
-	return cs_strm(si->cs)->task;
+	struct stream *strm = cs_strm(si->cs);
+
+	ALREADY_CHECKED(strm);
+	return strm->task;
 }
 
 /* returns the stream interface on the other side. Used during forwarding. */
 static inline struct stream_interface *si_opposite(struct stream_interface *si)
 {
-	return ((si->flags & SI_FL_ISBACK) ? cs_strm(si->cs)->csf->si : cs_strm(si->cs)->csb->si);
+	struct stream *strm = cs_strm(si->cs);
+
+	ALREADY_CHECKED(strm);
+	return ((si->flags & SI_FL_ISBACK) ? strm->csf->si : strm->csb->si);
 }
 
 /* initializes a stream interface in the SI_ST_INI state and create the event
diff --git a/src/hlua.c b/src/hlua.c
index 3b2bd73ef..8b42746d8 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -2685,6 +2685,7 @@ __LJMP static int hlua_socket_connect_yield(struct lua_State *L, int status, lua
 	}
 
 	appctx = cs_appctx(s->csf);
+	ALREADY_CHECKED(appctx);
 
 	/* Check for connection established. */
 	if (appctx->ctx.hlua_cosocket.connected) {
@@ -4272,7 +4273,10 @@ static int hlua_applet_tcp_new(lua_State *L, struct appctx *ctx)
 	struct hlua_appctx *luactx;
 	struct stream_interface *si = cs_si(ctx->owner);
 	struct stream *s = si_strm(si);
-	struct proxy *p = s->be;
+	struct proxy *p;
+
+	ALREADY_CHECKED(s);
+	p = s->be;
 
 	/* Check stack size. */
 	if (!lua_checkstack(L, 3))
diff --git a/src/http_ana.c b/src/http_ana.c
index a3fd15cb7..ff98a7bdd 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -3883,6 +3883,7 @@ static int http_handle_stats(struct stream *s, struct channel *req)
 	struct htx_sl *sl;
 
 	appctx = cs_appctx(s->csb);
+	ALREADY_CHECKED(appctx);
 	memset(&appctx->ctx.stats, 0, sizeof(appctx->ctx.stats));
 	appctx->st1 = appctx->st2 = 0;
 	appctx->ctx.stats.st_code = STAT_STATUS_INIT;
diff --git a/src/mux_pt.c b/src/mux_pt.c
index 9f1aaa877..1a706270f 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -407,7 +407,10 @@ static void mux_pt_destroy_meth(void *ctx)
 static void mux_pt_detach(struct conn_stream *cs)
 {
 	struct connection *conn = cs_conn(cs);
-	struct mux_pt_ctx *ctx = conn->ctx;
+	struct mux_pt_ctx *ctx;
+
+	ALREADY_CHECKED(conn);
+	ctx = conn->ctx;
 
 	TRACE_ENTER(PT_EV_STRM_END, conn, cs);
 
diff --git a/src/proxy.c b/src/proxy.c
index c392b4c6c..c486376a5 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -2613,7 +2613,7 @@ static void dump_server_addr(const struct sockaddr_storage *addr, char *addr_str
 static int dump_servers_state(struct stream_interface *si)
 {
 	struct appctx *appctx = cs_appctx(si->cs);
-	struct proxy *px = appctx->ctx.cli.p0;
+	struct proxy *px;
 	struct server *srv;
 	char srv_addr[INET6_ADDRSTRLEN + 1];
 	char srv_agent_addr[INET6_ADDRSTRLEN + 1];
@@ -2622,6 +2622,9 @@ static int dump_servers_state(struct stream_interface *si)
 	int bk_f_forced_id, srv_f_forced_id;
 	char *srvrecord;
 
+	ALREADY_CHECKED(appctx);
+	px = appctx->ctx.cli.p0;
+
 	if (!appctx->ctx.cli.p1)
 		appctx->ctx.cli.p1 = px->srv;
 
diff --git a/src/stats.c b/src/stats.c
index bffd3e395..854515b26 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -1984,6 +1984,8 @@ static int stats_dump_li_stats(struct stream_interface *si, struct proxy *px, st
 	struct stats_module *mod;
 	size_t stats_count = ST_F_TOTAL_FIELDS;
 
+	ALREADY_CHECKED(appctx);
+
 	memset(stats, 0, sizeof(struct field) * stat_count[STATS_DOMAIN_PROXY]);
 
 	if (!stats_fill_li_stats(px, l, appctx->ctx.stats.flags, stats,
@@ -2495,6 +2497,8 @@ static int stats_dump_sv_stats(struct stream_interface *si, struct proxy *px, st
 	struct field *stats = stat_l[STATS_DOMAIN_PROXY];
 	size_t stats_count = ST_F_TOTAL_FIELDS;
 
+	ALREADY_CHECKED(appctx);
+
 	memset(stats, 0, sizeof(struct field) * stat_count[STATS_DOMAIN_PROXY]);
 
 	if (!stats_fill_sv_stats(px, sv, appctx->ctx.stats.flags, stats,
@@ -4205,6 +4209,8 @@ static int stats_send_http_redirect(struct stream_interface *si, struct htx *htx
 	struct htx_sl *sl;
 	unsigned int flags;
 
+	ALREADY_CHECKED(appctx);
+
 	/* scope_txt = search pattern + search query, appctx->ctx.stats.scope_len is always <= STAT_SCOPE_TXT_MAXLEN */
 	scope_txt[0] = 0;
 	if (appctx->ctx.stats.scope_len) {
@@ -4518,6 +4524,8 @@ static int stats_dump_info_to_buffer(struct stream_interface *si)
 {
 	struct appctx *appctx = cs_appctx(si->cs);
 
+	ALREADY_CHECKED(appctx);
+
 	if (!stats_fill_info(info, INF_TOTAL_FIELDS, appctx->ctx.stats.flags))
 		return 0;
 
diff --git a/src/stream.c b/src/stream.c
index 935fce42d..37cd79378 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -980,11 +980,11 @@ enum act_return process_use_service(struct act_rule *rule, struct proxy *px,
 	if (flags & ACT_OPT_FIRST) {
 		/* Register applet. this function schedules the applet. */
 		s->target = &rule->applet.obj_type;
-		if (unlikely(!si_register_handler(cs_si(s->csb), objt_applet(s->target))))
+		appctx = si_register_handler(cs_si(s->csb), objt_applet(s->target));
+		if (unlikely(!appctx))
 			return ACT_RET_ERR;
 
 		/* Initialise the context. */
-		appctx = cs_appctx(s->csb);
 		memset(&appctx->ctx, 0, sizeof(appctx->ctx));
 		appctx->rule = rule;
 	}
@@ -3101,6 +3101,8 @@ static int stats_dump_full_strm_to_buffer(struct stream_interface *si, struct st
 	struct connection *conn;
 	struct appctx *tmpctx;
 
+	ALREADY_CHECKED(appctx);
+
 	chunk_reset(&trash);
 
 	if (appctx->ctx.sess.section > 0 && appctx->ctx.sess.uid != strm->uniq_id) {