diff --git a/pom.xml b/pom.xml
index dc7c298..ad4af5a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -133,7 +133,7 @@
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
-      <version>4.7</version>
+      <version>4.11</version>
       <scope>test</scope>
     </dependency>
     <dependency>
diff --git a/src/main/java/org/forkalsrud/album/video/FlvMetadata.java b/src/main/java/org/forkalsrud/album/video/FlvMetadata.java
index d68a6cc..b605315 100644
--- a/src/main/java/org/forkalsrud/album/video/FlvMetadata.java
+++ b/src/main/java/org/forkalsrud/album/video/FlvMetadata.java
@@ -32,6 +32,13 @@ public class FlvMetadata {
             this.value = value;
         }
 
+        @SuppressWarnings("unchecked")
+		public void merge(Attr<?> other) {
+        	if (other != null && other.getClass() == getClass()) {
+        		set((T)other.value);
+        	}
+        }
+
         public abstract void write(OutputStream out) throws IOException;
 
         public boolean isPresent() {
@@ -249,7 +256,7 @@ public class FlvMetadata {
 
     private LinkedList<Keyframe> keyframes = new LinkedList<Keyframe>();
 
-    private ArrayList<Attr> attrs = new ArrayList<Attr>();
+    private ArrayList<Attr<?>> attrs = new ArrayList<Attr<?>>();
 
     public FlvMetadata() {
 
@@ -304,7 +311,7 @@ public class FlvMetadata {
 
     private int length() {
         int i = 0;
-        for (Attr a : attrs) {
+        for (Attr<?> a : attrs) {
             if (a.isPresent()) {
                 i++;
             }
@@ -355,7 +362,7 @@ public class FlvMetadata {
         out.write(2);  // string
         writeFlvString(out, "onMetaData");
         writeFlvEcmaArray(out, length());
-        for (Attr a : attrs) {
+        for (Attr<?> a : attrs) {
             if (a.isPresent()) {
                 if (a.name != null) {
                     writeFlvString(out, a.name);
@@ -499,10 +506,10 @@ public class FlvMetadata {
     public void merge(FlvMetadata other) {
 
         for (int i = 0; i < attrs.size(); i++) {
-            Attr their = other.attrs.get(i);
+            Attr<?> their = other.attrs.get(i);
             if (their.isPresent()) {
-                Attr our = this.attrs.get(i);
-                our.set(their.value);
+                Attr<?> our = this.attrs.get(i);
+                our.merge(their);
             }
         }
     }
@@ -512,7 +519,7 @@ public class FlvMetadata {
         if (prop == null) {
             return null;
         }
-        for (Attr a : attrs) {
+        for (Attr<?> a : attrs) {
             if (prop.equals(a.name) && a.isPresent()) {
                 return a.value;
             }
@@ -637,13 +644,13 @@ public class FlvMetadata {
     protected void readProperty(InputStream in) throws FlvFormatException, IOException {
 
         String name = readString(in);
-        Attr attr = findAttrByName(name);
+        Attr<?> attr = findAttrByName(name);
         if (attr != null) {
             attr.read(in);
         } else {
         	log.warn("Unknown metadata property: " + name);
         	readUnknownProperty(in, name);
-        } 
+        }
     }
     
     protected void readUnknownProperty(InputStream in, String name) throws IOException, FlvFormatException {
@@ -660,8 +667,8 @@ public class FlvMetadata {
 		}
     }
     
-    private Attr findAttrByName(String name) {
-        for (Attr a : this.attrs) {
+    private Attr<?> findAttrByName(String name) {
+        for (Attr<?> a : this.attrs) {
             if (name.equals(a.name)) {
                 return a;
             }
@@ -716,8 +723,8 @@ public class FlvMetadata {
         }
         FlvMetadata other = (FlvMetadata)o;
         for (int i = 0; i < attrs.size(); i++) {
-            Attr their = other.attrs.get(i);
-            Attr our = this.attrs.get(i);
+            Attr<?> their = other.attrs.get(i);
+            Attr<?> our = this.attrs.get(i);
             if (our.isPresent() && their.isPresent()) {
                 if (!our.value.equals(their.value)) {
                     return false;
@@ -733,7 +740,7 @@ public class FlvMetadata {
     @Override
     public int hashCode() {
         int x = 0;
-        for (Attr a : attrs) {
+        for (Attr<?> a : attrs) {
             x *= 13;
             x += a.present ? a.value.hashCode() : 7;
         }
diff --git a/src/test/java/org/forkalsrud/album/video/FlvMetadataTest.java b/src/test/java/org/forkalsrud/album/video/FlvMetadataTest.java
index f6da237..9d8a572 100644
--- a/src/test/java/org/forkalsrud/album/video/FlvMetadataTest.java
+++ b/src/test/java/org/forkalsrud/album/video/FlvMetadataTest.java
@@ -5,10 +5,14 @@ import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 
 import org.forkalsrud.album.exif.Dimension;
+import org.junit.Test;
 
-import junit.framework.TestCase;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.hamcrest.core.IsInstanceOf.instanceOf;
 
-public class FlvMetadataTest extends TestCase {
+public class FlvMetadataTest {
 
     private ByteArrayOutputStream out = new ByteArrayOutputStream();
     private ByteArrayInputStream in;
@@ -19,6 +23,7 @@ public class FlvMetadataTest extends TestCase {
         out.reset();
     }
 
+    @Test
     public void testMerge() throws Exception {
 
         FlvMetadata md1 = new FlvMetadata();
@@ -27,19 +32,20 @@ public class FlvMetadataTest extends TestCase {
 
         FlvMetadata md2 = new FlvMetadata();
         md2.merge(md1);
-        assertEquals(Double.valueOf("3.14"), md2.get("duration"));
-        assertEquals(Double.valueOf("5"), md2.get("width"));
-        assertEquals(Double.valueOf("6"), md2.get("height"));
+        assertEquals(3.14d, md2.get("duration"));
+        assertEquals(5d, md2.get("width"));
+        assertEquals(6d, md2.get("height"));
     }
 
+    @Test
     public void testReadWriteDouble() throws Exception {
-
         double value = 3.14;
         md0.writeDouble(out, value);
         flip();
-        assertEquals(value, md0.readDouble(in));
+        assertThat(md0.readDouble(in), equalTo(value));
     }
 
+    @Test
     public void testReadWriteInt() throws Exception {
         int value = 45;
         // uint16
@@ -63,6 +69,7 @@ public class FlvMetadataTest extends TestCase {
         assertEquals(value, md0.readTimestamp(in));
     }
 
+    @Test
     public void testReadWriteString() throws Exception {
         String value = "awsome";
         md0.writeFlvString(out, value);
@@ -70,6 +77,7 @@ public class FlvMetadataTest extends TestCase {
         assertEquals(value, md0.readString(in));
     }
 
+    @Test
     public void testWriteReadMetadata() throws Exception {
 
         FlvMetadata md1 = new FlvMetadata();
@@ -88,6 +96,7 @@ public class FlvMetadataTest extends TestCase {
     }
 
 
+    @Test
     public void testReadWriteMetadata() throws Exception {
 
         InputStream is = getClass().getResourceAsStream("/VideoAd.flv");
@@ -105,12 +114,13 @@ public class FlvMetadataTest extends TestCase {
         assertEquals(md1, md2);
     }
 
+    @Test
     public void testSetDuration() {
     	FlvMetadata m = new FlvMetadata();
     	m.setDuration("1:02:03");
     	Object o = m.get("duration");
-    	assertTrue(o.getClass() == Double.class);
+    	assertThat(o, instanceOf(Double.class));
     	Double durationSeconds = (Double) o;
-    	assertEquals(3600 + 2*60 + 3, durationSeconds.intValue());
+    	assertThat(durationSeconds.intValue(), equalTo(3600 + 2*60 + 3));
     }
 }