diff --git a/src/main/java/net/marvk/fs/vatsim/map/data/FlightPlan.java b/src/main/java/net/marvk/fs/vatsim/map/data/FlightPlan.java
index e1bfe6c9..33df448d 100644
--- a/src/main/java/net/marvk/fs/vatsim/map/data/FlightPlan.java
+++ b/src/main/java/net/marvk/fs/vatsim/map/data/FlightPlan.java
@@ -278,7 +278,11 @@ private static String parseAltitude(final String altitude) {
 
                 final int multiplier = prefix == null ? 1 : 100;
 
-                return String.valueOf(Integer.parseInt(amount) * multiplier);
+                try {
+                    return String.valueOf(Integer.parseInt(amount) * multiplier);
+                } catch (NumberFormatException e) {
+                    return null;
+                }
             }
             return null;
         });