diff --git a/scp.c b/scp.c
index 7edc324d..ec910d4f 100644
--- a/scp.c
+++ b/scp.c
@@ -16252,7 +16252,9 @@ for (i = 0; (dptr = devices[i]) != NULL; i++) {
             }
         if (arptr != NULL) {
             Bad = TRUE;
-            Mprintf (f, "\tThe %s DEVICE %d REGister entry has an identical name\n", dptr->name, amb_entry);
+            if (rptr->source_file != NULL)
+                Mprintf (f, "\tIn %s at line %d:\n", rptr->source_file, rptr->source_line);
+            Mprintf (f, "\tThe %s DEVICE's REGister entry #%d has an identical name\n", dptr->name, amb_entry + 1);
             Mprintf (f, "\ttherefore EXAMINE and SAVE operations will reference %u byte%s\n", bytes, (bytes != 1) ? "s" : "");
             Mprintf (f, "\tand DEPOSIT and RESTORE operations will affect %u byte%s of memory\n", bytes, (bytes != 1) ? "s" : "");
             Mprintf (f, "\tinconsistently.\n");
diff --git a/sim_defs.h b/sim_defs.h
index 136e6d5e..c2e49ae0 100644
--- a/sim_defs.h
+++ b/sim_defs.h
@@ -705,6 +705,8 @@ struct REG {
     size_t              obj_size;                       /* sizeof(*loc) */
     size_t              size;                           /* sizeof(**loc) or sizeof(*loc) if depth == 1 */
     const char          *macro;                         /* Initializer Macro Name */
+    const char          *source_file;                   /* source file used macro */
+    int                 source_line;                    /* source line used macro */
     /* NOTE: Flags and maxval MUST always be last since they are initialized outside of macro definitions */
     uint32              flags;                          /* flags */
     t_value             maxval;                         /* maximum value */
@@ -1019,7 +1021,7 @@ struct MEMFILE {
 
 /* Internal use ONLY (see below) Generic Register declaration for all fields */
 #define _RegCheck(nm,loc,rdx,wd,off,dep,desc,flds,qptr,siz,elesiz,macro) \
-    nm, (loc), (rdx), (wd), (off), (dep), (desc), (flds), (qptr), (siz), sizeof(*(loc)), (elesiz), #macro
+    nm, (loc), (rdx), (wd), (off), (dep), (desc), (flds), (qptr), (siz), sizeof(*(loc)), (elesiz), #macro, __FILE__, __LINE__
 
 /* Generic Register declaration for all fields.  
    If the register structure is extended, this macro will be retained and a