diff --git a/src/include/switch_core.h b/src/include/switch_core.h
index 086f1965e3..f91ab74597 100644
--- a/src/include/switch_core.h
+++ b/src/include/switch_core.h
@@ -375,7 +375,7 @@ SWITCH_DECLARE(void *) switch_core_session_alloc(switch_core_session_t *session,
   \param todup the string to duplicate
   \return a pointer to the newly duplicated string
 */
-SWITCH_DECLARE(char *) switch_core_permanent_strdup(char *todup);
+SWITCH_DECLARE(char *) switch_core_permanent_strdup(const char *todup);
 
 /*! 
   \brief Copy a string using memory allocation from a session's pool
diff --git a/src/switch_core.c b/src/switch_core.c
index 907b3951cb..88d069fce3 100644
--- a/src/switch_core.c
+++ b/src/switch_core.c
@@ -1443,7 +1443,7 @@ SWITCH_DECLARE(void *) switch_core_permanent_alloc(switch_size_t memory)
 	return ptr;
 }
 
-SWITCH_DECLARE(char *) switch_core_permanent_strdup(char *todup)
+SWITCH_DECLARE(char *) switch_core_permanent_strdup(const char *todup)
 {
 	char *duped = NULL;
 	switch_size_t len;