diff --git a/core/src/main/java/com/graphhopper/routing/util/OSMParsers.java b/core/src/main/java/com/graphhopper/routing/util/OSMParsers.java
index 680aa3ab8e..71ee8a42fe 100644
--- a/core/src/main/java/com/graphhopper/routing/util/OSMParsers.java
+++ b/core/src/main/java/com/graphhopper/routing/util/OSMParsers.java
@@ -53,6 +53,7 @@ public OSMParsers(List<TagParser> wayTagParsers, List<VehicleTagParser> vehicleT
     }
 
     public OSMParsers addWayTagParser(TagParser tagParser) {
+        if (tagParser == null) throw new IllegalArgumentException("TagParser must not be null");
         wayTagParsers.add(tagParser);
         return this;
     }