diff --git a/src/os/rtems/inc/os-rtems.h b/src/os/rtems/inc/os-rtems.h
index f5d78fc01..4b9fd0998 100644
--- a/src/os/rtems/inc/os-rtems.h
+++ b/src/os/rtems/inc/os-rtems.h
@@ -47,6 +47,12 @@
 #include <rtems/malloc.h>
 #include <rtems/rtems/intr.h>
 
+#ifndef _RTEMS_5_
+
+#include <rtems/rtl/rtl.h> /* needed for RTEMS 4.11 alias */
+
+#endif
+
 #include "os-shared-globaldefs.h"
 
 /****************************************************************************************
@@ -62,17 +68,24 @@
 #define OSAL_UNRESOLVED_ITERATE rtems_rtl_unresolved_iterate
 
 #else
+
 #define OSAL_HEAP_INFO_BLOCK    region_information_block
 #define OSAL_UNRESOLV_REC_TYPE  rtems_rtl_unresolv_rec_t
 #define OSAL_UNRESOLVED_SYMBOL  rtems_rtl_unresolved_name
 #define OSAL_UNRESOLVED_ITERATE rtems_rtl_unresolved_interate
-typedef rtems_rtl_obj_t rtems_rtl_obj;
-#endif
+
+
 
 /****************************************************************************************
                                     TYPEDEFS
  ***************************************************************************************/
 
+#ifndef _RTEMS_5_
+
+typedef rtems_rtl_obj_t rtems_rtl_obj; /* Alias for RTEMS 4.11 */
+
+#endif
+
 typedef struct
 {
     uint32   ClockAccuracyNsec;