diff --git a/include/asterisk/pbx.h b/include/asterisk/pbx.h
index 9cc7f0b538..593b1861dc 100644
--- a/include/asterisk/pbx.h
+++ b/include/asterisk/pbx.h
@@ -1432,7 +1432,7 @@ void pbx_substitute_variables_helper_full(struct ast_channel *c, struct varshead
 /*!
  * \brief Substitutes variables, similar to pbx_substitute_variables_helper_full, but allows passing the context, extension, and priority in.
  */
-void pbx_substitute_variables_helper_full_location(struct ast_channel *c, struct varshead *headp, const char *cp1, char *cp2, int cp2_size, size_t *used, char *context, char *exten, int pri);
+void pbx_substitute_variables_helper_full_location(struct ast_channel *c, struct varshead *headp, const char *cp1, char *cp2, int cp2_size, size_t *used, const char *context, const char *exten, int pri);
 /*! @} */
 
 /*! @name Substitution routines, using dynamic string buffers
diff --git a/main/pbx_variables.c b/main/pbx_variables.c
index f589b6bce0..b05a9d11ca 100644
--- a/main/pbx_variables.c
+++ b/main/pbx_variables.c
@@ -662,7 +662,7 @@ void pbx_substitute_variables_helper_full(struct ast_channel *c, struct varshead
 	pbx_substitute_variables_helper_full_location(c, headp, cp1, cp2, count, used, NULL, NULL, 0);
 }
 
-void pbx_substitute_variables_helper_full_location(struct ast_channel *c, struct varshead *headp, const char *cp1, char *cp2, int count, size_t *used, char *context, char *exten, int pri)
+void pbx_substitute_variables_helper_full_location(struct ast_channel *c, struct varshead *headp, const char *cp1, char *cp2, int count, size_t *used, const char *context, const char *exten, int pri)
 {
 	/* Substitutes variables into cp2, based on string cp1, cp2 NO LONGER NEEDS TO BE ZEROED OUT!!!!  */
 	const char *whereweare;