diff --git a/ebean-core/src/main/java/io/ebeaninternal/server/type/DefaultTypeManager.java b/ebean-core/src/main/java/io/ebeaninternal/server/type/DefaultTypeManager.java
index bc7fc2f2d0..eb26c67342 100644
--- a/ebean-core/src/main/java/io/ebeaninternal/server/type/DefaultTypeManager.java
+++ b/ebean-core/src/main/java/io/ebeaninternal/server/type/DefaultTypeManager.java
@@ -346,7 +346,7 @@ public ScalarType<?> dbJsonType(DeployProperty prop, int dbType, int dbLength) {
 
   private boolean keepSource(DeployProperty prop) {
     if (prop.mutationDetection() == MutationDetection.DEFAULT) {
-      prop.setMutationDetection(jsonManager.mutationDetection());
+      prop.setMutationDetection(jsonManager != null ? jsonManager.mutationDetection() : MutationDetection.NONE);
     }
     return prop.mutationDetection() == MutationDetection.SOURCE;
   }