diff --git a/funcs/func_callerid.c b/funcs/func_callerid.c
index e53097f3b4..9dfe0d8c7c 100644
--- a/funcs/func_callerid.c
+++ b/funcs/func_callerid.c
@@ -72,6 +72,8 @@ static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 			ast_log(LOG_ERROR, "Unknown callerid data type '%s'.\n", data);
 		}
 	} else {
+		ast_channel_lock(chan);
+
 		if (!strncasecmp("all", data, 3)) {
 			snprintf(buf, len, "\"%s\" <%s>",
 				 S_OR(chan->cid.cid_name, ""),
@@ -105,6 +107,8 @@ static int callerid_read(struct ast_channel *chan, const char *cmd, char *data,
 		} else {
 			ast_log(LOG_ERROR, "Unknown callerid data type '%s'.\n", data);
 		}
+
+		ast_channel_unlock(chan);
 	}
 
 	return 0;
@@ -133,15 +137,17 @@ static int callerid_write(struct ast_channel *chan, const char *cmd, char *data,
 		} else
 			ast_set_callerid(chan, NULL, NULL, value);
 	} else if (!strncasecmp("dnid", data, 4)) {
-		/* do we need to lock chan here? */
+		ast_channel_lock(chan);
 		if (chan->cid.cid_dnid)
 			ast_free(chan->cid.cid_dnid);
 		chan->cid.cid_dnid = ast_strdup(value);
+		ast_channel_unlock(chan);
 	} else if (!strncasecmp("rdnis", data, 5)) {
-		/* do we need to lock chan here? */
+		ast_channel_lock(chan);
 		if (chan->cid.cid_rdnis)
 			ast_free(chan->cid.cid_rdnis);
 		chan->cid.cid_rdnis = ast_strdup(value);
+		ast_channel_unlock(chan);
 	} else if (!strncasecmp("pres", data, 4)) {
 		int i;
 		char *s, *val;
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index ad4e735b88..4bf33d7bd1 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -1309,7 +1309,11 @@ int ast_activate_generator(struct ast_channel *chan, struct ast_generator *gen,
 /*! Deactivate an active generator */
 void ast_deactivate_generator(struct ast_channel *chan);
 
-/*! Set caller ID number, name and ANI */
+/*!
+ * \brief Set caller ID number, name and ANI
+ *
+ * \note The channel does not need to be locked before calling this function.
+ */
 void ast_set_callerid(struct ast_channel *chan, const char *cid_num, const char *cid_name, const char *cid_ani);
 
 /*! Set the file descriptor on the channel */
diff --git a/main/channel.c b/main/channel.c
index 0dd937c1e2..219485939e 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -3758,6 +3758,8 @@ int ast_do_masquerade(struct ast_channel *original)
 
 void ast_set_callerid(struct ast_channel *chan, const char *cid_num, const char *cid_name, const char *cid_ani)
 {
+	ast_channel_lock(chan);
+
 	if (cid_num) {
 		if (chan->cid.cid_num)
 			ast_free(chan->cid.cid_num);
@@ -3788,6 +3790,8 @@ void ast_set_callerid(struct ast_channel *chan, const char *cid_num, const char
 				chan->cid.cid_pres,
 				ast_describe_caller_presentation(chan->cid.cid_pres)
 				);
+	
+	ast_channel_unlock(chan);
 }
 
 int ast_setstate(struct ast_channel *chan, enum ast_channel_state state)