graphql-java
diff --git a/‎src/main/java/graphql/schema/idl/TypeDefinitionRegistry.java‎
Lines changed: 10 additions & 3 deletions b/‎src/main/java/graphql/schema/idl/TypeDefinitionRegistry.java‎
Lines changed: 10 additions & 3 deletions
diff --git a/‎src/main/java/graphql/schema/idl/TypeInfo.java‎
Lines changed: 11 additions & 9 deletions b/‎src/main/java/graphql/schema/idl/TypeInfo.java‎
Lines changed: 11 additions & 9 deletions
@@ -623,9 +623,16 @@ public boolean isPossibleType(Type abstractType, Type possibleType) {
             return false;
         } else {
             InterfaceTypeDefinition iFace = (InterfaceTypeDefinition) abstractTypeDef;
-            List<ImplementingTypeDefinition> implementingTypeDefinitions = getAllImplementationsOf(iFace);
-            return implementingTypeDefinitions.stream()
-                    .anyMatch(od -> od.getName().equals(targetObjectTypeDef.getName()));
+
+            return types.values().stream()
+                    .filter(ImplementingTypeDefinition.class::isInstance)
+                    .filter(t -> t.getName().equals(targetObjectTypeDef.getName()))
+                    .map(td -> (ImplementingTypeDefinition<?>) td)
+                    .anyMatch(itd -> itd.getImplements()
+                            .stream()
+                            .map(TypeInfo::getTypeName)
+                            .anyMatch(tn -> tn.getName().equals(iFace.getName()))
+                    );
         }
     }
 
 
@@ -26,23 +26,25 @@ public static TypeInfo typeInfo(Type type) {
         return new TypeInfo(type);
     }
 
-    private final Type rawType;
-    private final TypeName typeName;
-    private final Deque<Class<?>> decoration = new ArrayDeque<>();
-
-    private TypeInfo(Type type) {
-        this.rawType = assertNotNull(type, () -> "type must not be null");
+    public static TypeName getTypeName(Type type) {
         while (!(type instanceof TypeName)) {
             if (type instanceof NonNullType) {
-                decoration.push(NonNullType.class);
                 type = ((NonNullType) type).getType();
             }
             if (type instanceof ListType) {
-                decoration.push(ListType.class);
                 type = ((ListType) type).getType();
             }
         }
-        this.typeName = (TypeName) type;
+        return (TypeName) type;
+    }
+
+    private final Type rawType;
+    private final TypeName typeName;
+    private final Deque<Class<?>> decoration = new ArrayDeque<>();
+
+    private TypeInfo(Type type) {
+        this.rawType = assertNotNull(type, () -> "type must not be null");
+        this.typeName = getTypeName(type);
     }
 
     public Type getRawType() {