diff --git a/src/include/switch_channel.h b/src/include/switch_channel.h
index 80057584bc..5ee25be3b8 100644
--- a/src/include/switch_channel.h
+++ b/src/include/switch_channel.h
@@ -455,7 +455,7 @@ SWITCH_DECLARE(void) switch_channel_event_set_data(switch_channel_t *channel, sw
   \return the original string if no expansion takes place otherwise a new string that must be freed
   \note it's necessary to test if the return val is the same as the input and free the string if it is not.
 */
-SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel, char *in);
+SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel, const char *in);
 SWITCH_DECLARE(char *) switch_channel_build_param_string(switch_channel_t *channel, switch_caller_profile_t *caller_profile, const char *prefix);
 
 /** @} */
diff --git a/src/switch_channel.c b/src/switch_channel.c
index ebe61565c6..82ff540b7e 100644
--- a/src/switch_channel.c
+++ b/src/switch_channel.c
@@ -1264,12 +1264,12 @@ if ((dp = realloc(data, olen))) {\
     memset(c, 0, olen - cpos);\
  }}                           \
 
-SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel, char *in)
+SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel, const char *in)
 {
-	char *q, *p, *c = NULL;
+	char *p, *c = NULL;
 	char *data, *indup;
 	size_t sp = 0, len = 0, olen = 0, vtype = 0, br = 0, cpos, block = 128;
-	const char *sub_val = NULL;
+	const char *q, *sub_val = NULL;
 	char *cloned_sub_val = NULL;
 	char *func_val = NULL;
 	int nv = 0;
@@ -1295,7 +1295,7 @@ SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel
 	}
 	
 	if (!nv) {
-		return in;
+		return (char *)in;
 	}
 
 	nv = 0;
@@ -1468,7 +1468,7 @@ SWITCH_DECLARE(char *) switch_channel_expand_variables(switch_channel_t *channel
 						switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_CRIT, "Memory Error!\n");
 						free(data);
 						free(indup);
-						return in;
+						return (char *)in;
 					}
 				}
 				if ((nlen = sub_val ? strlen(sub_val) : 0)) {