diff --git a/src/test/java/io/usethesource/capsule/AbstractMapProperties.java b/src/test/java/io/usethesource/capsule/AbstractMapProperties.java
index 1183c98..037d6c5 100644
--- a/src/test/java/io/usethesource/capsule/AbstractMapProperties.java
+++ b/src/test/java/io/usethesource/capsule/AbstractMapProperties.java
@@ -13,6 +13,7 @@
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Objects;
 
@@ -27,6 +28,22 @@
  */
 public abstract class AbstractMapProperties<T, CT extends Map.Immutable<T, T>> {
 
+  @Property(trials = DEFAULT_TRIALS)
+  public void convertToJavaMapAndCheckSize(CT input) {
+    assertEquals(new HashMap<T, T>(input).size(), input.size());
+  }
+
+  @Property(trials = DEFAULT_TRIALS)
+  public void convertToJavaMapAndCheckHashCode(CT input) {
+    assertEquals(new HashMap<T, T>(input).hashCode(), input.hashCode());
+  }
+
+  @Property(trials = DEFAULT_TRIALS)
+  public void convertToJavaMapAndCheckEquality(CT input) {
+    assertEquals("input.equals(convertToJavaSet)", input, new HashMap<T, T>(input));
+    assertEquals("convertToJavaSet.equals(input)", new HashMap<T, T>(input), input);
+  }
+
   @Property(trials = DEFAULT_TRIALS)
   public void serializationRoundtrip(CT input) throws Exception {
     assertEquals(input, deserialize(serialize((Serializable) input), input.getClass()));