diff --git a/src/share/classes/jdk/codetools/apidiff/model/API.java b/src/share/classes/jdk/codetools/apidiff/model/API.java
index 730d5cd..110bc1e 100644
--- a/src/share/classes/jdk/codetools/apidiff/model/API.java
+++ b/src/share/classes/jdk/codetools/apidiff/model/API.java
@@ -358,6 +358,11 @@ private class LocationAndKinds {
                 this.locn = locn;
                 this.kinds = kinds;
             }
+
+            @Override
+            public String toString() {
+                return getClass().getSimpleName() + "[locn:" + locn + ",kinds:" + kinds + "]";
+            }
         }
 
         private Map<String, LocationAndKinds> moduleLocationAndKinds;
diff --git a/src/share/classes/jdk/codetools/apidiff/model/Selector.java b/src/share/classes/jdk/codetools/apidiff/model/Selector.java
index 78f8b6c..d58ce78 100644
--- a/src/share/classes/jdk/codetools/apidiff/model/Selector.java
+++ b/src/share/classes/jdk/codetools/apidiff/model/Selector.java
@@ -178,6 +178,14 @@ boolean excludesType(String moduleName, String packageName, String typeName) {
             return excludesPackage(moduleName, packageName)
                     || includesPackage(moduleName, packageName) && excludeType.test(typeName);
         }
+
+        @Override
+        public String toString() {
+            return getClass().getSimpleName() + "[modulePart:" + modulePart
+                    + ",packagePart:" + packagePart
+                    + ",typePart:" + typePart
+                    + "]";
+        }
     }
 
     final List<Entry> includes;