diff --git a/dump1090.h b/dump1090.h
index 5f8ce7f..659c081 100644
--- a/dump1090.h
+++ b/dump1090.h
@@ -164,12 +164,13 @@
 #define MODES_ACFLAGS_NSEWSPD_VALID  (1<<14) // Aircraft EW and NS Speed is known
 #define MODES_ACFLAGS_LATLON_REL_OK  (1<<15) // Indicates it's OK to do a relative CPR
 #define MODES_ACFLAGS_REL_CPR_USED   (1<<16) // Lat/lon derived from relative CPR
-#define MODES_ACFLAGS_NON_ICAO       (1<<17) // Address is not ICAO-format
 
 #define MODES_ACFLAGS_LLEITHER_VALID (MODES_ACFLAGS_LLEVEN_VALID | MODES_ACFLAGS_LLODD_VALID)
 #define MODES_ACFLAGS_LLBOTH_VALID   (MODES_ACFLAGS_LLEVEN_VALID | MODES_ACFLAGS_LLODD_VALID)
 #define MODES_ACFLAGS_AOG_GROUND     (MODES_ACFLAGS_AOG_VALID    | MODES_ACFLAGS_AOG)
 
+#define MODES_NON_ICAO_ADDRESS       (1<<24) // Set on addresses to indicate they are not ICAO addresses
+
 #define MODES_DEBUG_DEMOD (1<<0)
 #define MODES_DEBUG_DEMODERR (1<<1)
 #define MODES_DEBUG_BADCRC (1<<2)
diff --git a/interactive.c b/interactive.c
index fc44b38..0dcb227 100644
--- a/interactive.c
+++ b/interactive.c
@@ -523,10 +523,10 @@ void interactiveShowData(void) {
 
     if (Modes.interactive_rtl1090 == 0) {
         printf (
-"Hex     Mode  Sqwk  Flight   Alt    Spd  Hdg    Lat      Long   RSSI  Msgs  Ti%c\n", progress);
+" Hex    Mode  Sqwk  Flight   Alt    Spd  Hdg    Lat      Long   RSSI  Msgs  Ti%c\n", progress);
     } else {
         printf (
-"Hex    Flight   Alt      V/S GS  TT  SSR  G*456^ Msgs    Seen %c\n", progress);
+" Hex   Flight   Alt      V/S GS  TT  SSR  G*456^ Msgs    Seen %c\n", progress);
     }
     printf(
 "-------------------------------------------------------------------------------\n");
@@ -601,8 +601,8 @@ void interactiveShowData(void) {
                         snprintf(strFl, 6, "%5d", altitude);
                     }
 
-                    printf("%06X%s %-4s  %-4s  %-8s %5s  %3s  %3s  %7s %8s %5.1f %5d %2d\n",
-                           a->addr, (a->bFlags & MODES_ACFLAGS_NON_ICAO) ? "~" : " ",
+                    printf("%s%06X %-4s  %-4s  %-8s %5s  %3s  %3s  %7s %8s %5.1f %5d %2d\n",
+                           (a->addr & MODES_NON_ICAO_ADDRESS) ? "~" : " ", (a->addr & 0xffffff),
                            strMode, strSquawk, a->flight, strFl, strGs, strTt,
                            strLat, strLon, 10 * log10(signalAverage), msgs, (int)(now - a->seen));
                 }
diff --git a/mode_ac.c b/mode_ac.c
index 04e522d..b4ecd11 100644
--- a/mode_ac.c
+++ b/mode_ac.c
@@ -364,14 +364,12 @@ void decodeModeAMessage(struct modesMessage *mm, int ModeA)
   mm->msg[0] = (ModeA >> 8);
   mm->msg[1] = (ModeA);
 
-  // Fudge an ICAO address based on Mode A (remove the Ident bit)
-  // Use an upper address byte of FF, since this is ICAO unallocated
-  mm->addr = 0x00FF0000 | (ModeA & 0x0000FF7F);
+  // Fudge an address based on Mode A (remove the Ident bit)
+  mm->addr = (ModeA & 0x0000FF7F) | MODES_NON_ICAO_ADDRESS;
 
   // Set the Identity field to ModeA
   mm->modeA   = ModeA & 0x7777;
   mm->bFlags |= MODES_ACFLAGS_SQUAWK_VALID;
-  mm->bFlags |= MODES_ACFLAGS_NON_ICAO;
 
   // Flag ident in flight status
   mm->fs = ModeA & 0x0080;
diff --git a/mode_s.c b/mode_s.c
index 0df3d4a..042dfe1 100644
--- a/mode_s.c
+++ b/mode_s.c
@@ -545,8 +545,9 @@ int decodeModesMessage(struct modesMessage *mm, unsigned char *msg)
         mm->addr  = (msg[1] << 16) | (msg[2] << 8) | (msg[3]);
 
         if (mm->msgtype == 18 && (mm->cf != 0 && mm->cf != 6))
-            mm->bFlags |= MODES_ACFLAGS_NON_ICAO; // DF 18 message not using ICAO addressing
-        else if (!mm->correctedbits && (mm->msgtype != 11 || mm->iid == 0)) {
+            mm->addr |= MODES_NON_ICAO_ADDRESS; // don't confuse this with any ICAO address
+
+        if (!mm->correctedbits && (mm->msgtype != 11 || mm->iid == 0)) {
             // No CRC errors seen, and either it was an DF17/18 extended squitter
             // or a DF11 acquisition squitter with II = 0. We probably have the right address.
 
diff --git a/net_io.c b/net_io.c
index 1a7dda5..ba71b59 100644
--- a/net_io.c
+++ b/net_io.c
@@ -749,7 +749,7 @@ char *generateAircraftJson(const char *url_path, int *len) {
         else
             *p++ = ',';
             
-        p += snprintf(p, end-p, "\n    {\"hex\":\"%06x%s\"", a->addr, (a->bFlags & MODES_ACFLAGS_NON_ICAO) ? "~" : "");
+        p += snprintf(p, end-p, "\n    {\"hex\":\"%s%06x\"", (a->addr & MODES_NON_ICAO_ADDRESS) ? "~" : "", a->addr & 0xFFFFFF);
         if (a->bFlags & MODES_ACFLAGS_SQUAWK_VALID)
             p += snprintf(p, end-p, ",\"squawk\":\"%04x\"", a->modeA);
         if (a->bFlags & MODES_ACFLAGS_CALLSIGN_VALID)
@@ -1311,14 +1311,14 @@ static void writeFATSV() {
         char *p, *end;
 
         // skip non-ICAO
-        if (a->bFlags & MODES_ACFLAGS_NON_ICAO)
+        if (a->addr & MODES_NON_ICAO_ADDRESS)
             continue;
 
         // don't emit if it hasn't updated since last time
         if (a->seen < a->fatsv_last_emitted) {
             continue;
         }
-        
+
         emittedSecondsAgo = (int)(now - a->fatsv_last_emitted);
 
         // don't emit more than once every five seconds