diff --git a/include/uxr/client/core/session/create_entities_ref.h b/include/uxr/client/core/session/create_entities_ref.h
index 7b4afd35..4049e5d6 100644
--- a/include/uxr/client/core/session/create_entities_ref.h
+++ b/include/uxr/client/core/session/create_entities_ref.h
@@ -51,7 +51,7 @@ UXRDLLAPI uint16_t uxr_buffer_create_participant_ref(
         uxrSession* session,
         uxrStreamId stream_id,
         uxrObjectId object_id,
-        int16_t domain_id,
+        uint16_t domain_id,
         const char* ref,
         uint8_t mode);
 
diff --git a/src/c/core/session/create_entities_ref.c b/src/c/core/session/create_entities_ref.c
index f64cfeaf..9c446319 100644
--- a/src/c/core/session/create_entities_ref.c
+++ b/src/c/core/session/create_entities_ref.c
@@ -20,7 +20,7 @@ uint16_t uxr_buffer_create_participant_ref(
         uxrSession* session,
         uxrStreamId stream_id,
         uxrObjectId object_id,
-        int16_t domain_id,
+        uint16_t domain_id,
         const char* ref,
         uint8_t mode)
 {