diff --git a/mod_unimrcp.c b/mod_unimrcp.c
index 5fb772f..5faac64 100644
--- a/mod_unimrcp.c
+++ b/mod_unimrcp.c
@@ -1459,7 +1459,7 @@ static const char *speech_channel_type_to_string(speech_channel_type_t type)
 static switch_status_t speech_channel_set_param(speech_channel_t *schannel, const char *param, const char *val)
 {
 	switch_mutex_lock(schannel->mutex);
-	if (!zstr(param) && val != NULL) {
+	if (!zstr(param) && val != NULL && schannel->params) {
 		/* check if this is a FreeSWITCH param that needs to be translated to an MRCP param: e.g. voice ==> voice-name */
 		const char *v;
 		const char *p = switch_core_hash_find(schannel->application->fs_param_map, param);
@@ -2428,8 +2428,8 @@ static switch_status_t recog_channel_load_grammar(speech_channel_t *schannel, co
 	}
 
 	/* Create the grammar and save it */
-	if ((status = grammar_create(&g, name, type, data, schannel->memory_pool)) == SWITCH_STATUS_SUCCESS) {
-		recognizer_data_t *r = (recognizer_data_t *) schannel->data;
+	recognizer_data_t *r = (recognizer_data_t *) schannel->data;
+	if (r->grammars && (status = grammar_create(&g, name, type, data, schannel->memory_pool)) == SWITCH_STATUS_SUCCESS) {
 		switch_core_hash_insert(r->grammars, g->name, g);
 	}
 
@@ -2459,8 +2459,12 @@ static switch_status_t recog_channel_unload_grammar(speech_channel_t *schannel,
 		switch_log_printf(SWITCH_CHANNEL_UUID_LOG(schannel->session_uuid), SWITCH_LOG_DEBUG, "(%s) Unloading grammar %s\n", schannel->name, grammar_name);
 
 		switch_mutex_lock(schannel->mutex);
-		switch_core_hash_delete(r->enabled_grammars, grammar_name);
-		switch_core_hash_delete(r->grammars, grammar_name);
+		if (r->enabled_grammars) {
+			switch_core_hash_delete(r->enabled_grammars, grammar_name);
+		}
+		if (r->grammars) {
+			switch_core_hash_delete(r->grammars, grammar_name);
+		}
 		switch_mutex_unlock(schannel->mutex);
 	}
 
@@ -2485,13 +2489,12 @@ static switch_status_t recog_channel_enable_grammar(speech_channel_t *schannel,
 		grammar_t *grammar;
 
 		switch_mutex_lock(schannel->mutex);
-		grammar = (grammar_t *) switch_core_hash_find(r->grammars, grammar_name);
-		if (grammar == NULL)
+		if (r->grammars && (grammar = (grammar_t *) switch_core_hash_find(r->grammars, grammar_name)) == NULL)
 		{
 			switch_log_printf(SWITCH_CHANNEL_UUID_LOG(schannel->session_uuid), SWITCH_LOG_ERROR, "(%s) Undefined grammar, %s\n", schannel->name, grammar_name);
 			status = SWITCH_STATUS_FALSE;
 		}
-		else {
+		else if (r->enabled_grammars) {
 			switch_log_printf(SWITCH_CHANNEL_UUID_LOG(schannel->session_uuid), SWITCH_LOG_DEBUG, "(%s) Enabling grammar %s\n", schannel->name, grammar_name);
 			switch_core_hash_insert(r->enabled_grammars, grammar_name, grammar);
 		}
@@ -2519,7 +2522,9 @@ static switch_status_t recog_channel_disable_grammar(speech_channel_t *schannel,
 		switch_log_printf(SWITCH_CHANNEL_UUID_LOG(schannel->session_uuid), SWITCH_LOG_DEBUG, "(%s) Disabling grammar %s\n", schannel->name, grammar_name);
 
 		switch_mutex_lock(schannel->mutex);
-		switch_core_hash_delete(r->enabled_grammars, grammar_name);
+		if (r->enabled_grammars) {
+			switch_core_hash_delete(r->enabled_grammars, grammar_name);
+		}
 		switch_mutex_unlock(schannel->mutex);
 	}
 
@@ -2534,14 +2539,17 @@ static switch_status_t recog_channel_disable_grammar(speech_channel_t *schannel,
  */
 static switch_status_t recog_channel_disable_all_grammars(speech_channel_t *schannel)
 {
-	switch_status_t status = SWITCH_STATUS_SUCCESS;
+	switch_status_t status = SWITCH_STATUS_FALSE;
 
 	recognizer_data_t *r = (recognizer_data_t *) schannel->data;
 	switch_log_printf(SWITCH_CHANNEL_UUID_LOG(schannel->session_uuid), SWITCH_LOG_DEBUG, "(%s) Disabling all grammars\n", schannel->name);
 
 	switch_mutex_lock(schannel->mutex);
-	switch_core_hash_destroy(&r->enabled_grammars);
-	switch_core_hash_init(&r->enabled_grammars);
+	if (r->enabled_grammars) {
+		switch_core_hash_destroy(&r->enabled_grammars);
+		switch_core_hash_init(&r->enabled_grammars);
+		status = SWITCH_STATUS_SUCCESS;
+	}
 	switch_mutex_unlock(schannel->mutex);
 
 	return status;