diff --git a/dump1090.h b/dump1090.h
index 9ceafae..9e0d862 100644
--- a/dump1090.h
+++ b/dump1090.h
@@ -381,6 +381,7 @@ struct modesMessage {
     int    heading;             // Reported by aircraft, or computed from from EW and NS velocity
     int    raw_latitude;        // Non decoded latitude.
     int    raw_longitude;       // Non decoded longitude.
+    unsigned nuc_p;             // NUCp value implied by message type
     double fLat;                // Coordinates obtained from CPR encoded data if/when decoded
     double fLon;                // Coordinates obtained from CPR encoded data if/when decoded
     char   flight[16];          // 8 chars flight number.
diff --git a/mode_s.c b/mode_s.c
index 87bdfcc..2f70f1f 100644
--- a/mode_s.c
+++ b/mode_s.c
@@ -838,7 +838,8 @@ static void decodeExtendedSquitter(struct modesMessage *mm)
             mm->bFlags |= MODES_ACFLAGS_HEADING_VALID;
             mm->heading = ((((msg[5] << 4) | (msg[6] >> 4)) & 0x007F) * 45) >> 4;
         }
-        
+
+        mm->nuc_p = (14 - metype);
         break;
     }
 
@@ -878,6 +879,13 @@ static void decodeExtendedSquitter(struct modesMessage *mm)
             mm->bFlags |= MODES_ACFLAGS_ALTITUDE_VALID;
             mm->altitude = decodeAC12Field(AC12Field, &mm->unit);
         }
+
+        if (metype == 0 || metype == 18 || metype == 22)
+            mm->nuc_p = 0;
+        else if (metype < 18)
+            mm->nuc_p = (18 - metype);
+        else
+            mm->nuc_p = (29 - metype);
         
         break;
     }
@@ -986,11 +994,13 @@ static void displayExtendedSquitter(struct modesMessage *mm) {
                 printf("    Global CPR decoding used.\n");
             printf("    Latitude : %f (%d)\n", mm->fLat, mm->raw_latitude);
             printf("    Longitude: %f (%d)\n", mm->fLon, mm->raw_longitude);
+            printf("    NUCp:      %u\n", mm->nuc_p);
         } else {
             if (!(mm->bFlags & MODES_ACFLAGS_LLEITHER_VALID))
                 printf("    Bad position data, not decoded.\n");
             printf("    Latitude : %d (not decoded)\n", mm->raw_latitude);
             printf("    Longitude: %d (not decoded)\n", mm->raw_longitude);
+            printf("    NUCp:      %u\n", mm->nuc_p);
         }
     } else if (mm->metype == 28) { // Extended Squitter Aircraft Status
         if (mm->mesub == 1) {