diff --git a/core/src/main/java/com/graphhopper/routing/Router.java b/core/src/main/java/com/graphhopper/routing/Router.java
index 204eb668f5e..b7ea9f340d3 100644
--- a/core/src/main/java/com/graphhopper/routing/Router.java
+++ b/core/src/main/java/com/graphhopper/routing/Router.java
@@ -49,11 +49,11 @@
 
 import java.util.*;
 
-import static com.graphhopper.util.TurnCostsConfig.INFINITE_U_TURN_COSTS;
 import static com.graphhopper.util.DistanceCalcEarth.DIST_EARTH;
 import static com.graphhopper.util.Parameters.Algorithms.ALT_ROUTE;
 import static com.graphhopper.util.Parameters.Algorithms.ROUND_TRIP;
 import static com.graphhopper.util.Parameters.Routing.*;
+import static com.graphhopper.util.TurnCostsConfig.INFINITE_U_TURN_COSTS;
 
 public class Router {
     protected final BaseGraph graph;
@@ -103,6 +103,7 @@ public GHResponse route(GHRequest request) {
             checkPointHints(request);
             checkCurbsides(request);
             checkNoBlockArea(request);
+            checkCustomModel(request);
 
             Solver solver = createSolver(request);
             solver.checkRequest();
@@ -180,6 +181,11 @@ private void checkNoBlockArea(GHRequest request) {
             throw new IllegalArgumentException("The `block_area` parameter is no longer supported. Use a custom model with `areas` instead.");
     }
 
+    private void checkCustomModel(GHRequest request) {
+        if (request.getCustomModel() != null && request.getCustomModel().isInternal())
+            throw new IllegalArgumentException("CustomModel of query cannot be internal");
+    }
+
     protected Solver createSolver(GHRequest request) {
         final boolean disableCH = getDisableCH(request.getHints());
         final boolean disableLM = getDisableLM(request.getHints());
diff --git a/core/src/main/java/com/graphhopper/routing/weighting/custom/FindMinMax.java b/core/src/main/java/com/graphhopper/routing/weighting/custom/FindMinMax.java
index 06b8245ba0a..6d4ffb520c0 100644
--- a/core/src/main/java/com/graphhopper/routing/weighting/custom/FindMinMax.java
+++ b/core/src/main/java/com/graphhopper/routing/weighting/custom/FindMinMax.java
@@ -35,8 +35,6 @@ public class FindMinMax {
      * is based on baseModel).
      */
     public static void checkLMConstraints(CustomModel baseModel, CustomModel queryModel, EncodedValueLookup lookup) {
-        if (queryModel.isInternal())
-            throw new IllegalArgumentException("CustomModel of query cannot be internal");
         if (queryModel.getDistanceInfluence() != null) {
             double bmDI = baseModel.getDistanceInfluence() == null ? 0 : baseModel.getDistanceInfluence();
             if (queryModel.getDistanceInfluence() < bmDI)