diff --git a/src/main/java/net/sourceforge/plantuml/servlet/ImgServlet.java b/src/main/java/net/sourceforge/plantuml/servlet/ImgServlet.java
index 12941be..3598f99 100644
--- a/src/main/java/net/sourceforge/plantuml/servlet/ImgServlet.java
+++ b/src/main/java/net/sourceforge/plantuml/servlet/ImgServlet.java
@@ -34,7 +34,7 @@ public class ImgServlet extends UmlDiagramService {
 
     @Override
     public String getSource(String uri) {
-        String[] result = uri.split("/img/", 2);
+        String[] result = uri.split("/img/|/png/", 2);
         if (result.length != 2) {
             return "";
         } else {
diff --git a/src/main/webapp/WEB-INF/web.xml b/src/main/webapp/WEB-INF/web.xml
index 222fc12..1523ca5 100644
--- a/src/main/webapp/WEB-INF/web.xml
+++ b/src/main/webapp/WEB-INF/web.xml
@@ -52,6 +52,10 @@
 		<servlet-name>plantumlservlet</servlet-name>
 		<url-pattern>/form</url-pattern>
 	</servlet-mapping>
+    <servlet-mapping>
+        <servlet-name>imgservlet</servlet-name>
+        <url-pattern>/png/*</url-pattern>
+    </servlet-mapping>
 	<servlet-mapping>
 		<servlet-name>imgservlet</servlet-name>
 		<url-pattern>/img/*</url-pattern>
diff --git a/src/main/webapp/index.jsp b/src/main/webapp/index.jsp
index 4d4f716..0680eab 100644
--- a/src/main/webapp/index.jsp
+++ b/src/main/webapp/index.jsp
@@ -7,7 +7,7 @@
     <c:set var="hostpath" value="http://${pageContext.request.serverName}${contextroot}" />
 </c:if>
 <c:if test="${!empty encoded}">
-    <c:set var="imgurl" value="${hostpath}/img/${encoded}" />
+    <c:set var="imgurl" value="${hostpath}/png/${encoded}" />
     <c:set var="svgurl" value="${hostpath}/svg/${encoded}" />
     <c:set var="txturl" value="${hostpath}/txt/${encoded}" />
     <c:if test="${!empty mapneeded}">
diff --git a/src/test/java/net/sourceforge/plantuml/servlet/TestForm.java b/src/test/java/net/sourceforge/plantuml/servlet/TestForm.java
index 6d4a509..8b63a88 100644
--- a/src/test/java/net/sourceforge/plantuml/servlet/TestForm.java
+++ b/src/test/java/net/sourceforge/plantuml/servlet/TestForm.java
@@ -20,7 +20,7 @@ public class TestForm extends WebappTestCase {
         WebForm forms[] = response.getForms();
         assertEquals(2, forms.length);
         assertEquals("url", forms[1].getParameterNames()[0]);
-        assertTrue(forms[1].getParameterValue("url").endsWith("/img/" + TestUtils.SEQBOB));
+        assertTrue(forms[1].getParameterValue("url").endsWith("/png/" + TestUtils.SEQBOB));
         // Ensure the generated image is present
         assertEquals(1, response.getImages().length);
 
@@ -43,7 +43,7 @@ public class TestForm extends WebappTestCase {
         // Ensure the Text field is correct
         assertEquals("version", forms[0].getParameterValue("text"));
         // Ensure the URL field is correct
-        assertTrue(forms[1].getParameterValue("url").endsWith("/img/" + TestUtils.VERSION));
+        assertTrue(forms[1].getParameterValue("url").endsWith("/png/" + TestUtils.VERSION));
         // Ensure the image is present
         assertEquals(1, response.getImages().length);
     }
@@ -109,7 +109,7 @@ public class TestForm extends WebappTestCase {
         // Ensure the Text field is correct
         assertTrue(forms[0].getParameterValue("text").startsWith("@startditaa"));
         // Ensure the URL field is correct
-        assertTrue(forms[1].getParameterValue("url").endsWith("/img/SoWkIImgISaiIKnKuDBIrRLJu798pKi12m00"));
+        assertTrue(forms[1].getParameterValue("url").endsWith("/png/SoWkIImgISaiIKnKuDBIrRLJu798pKi12m00"));
         // Ensure the image is present
         assertEquals(1, response.getImages().length);
     }
@@ -148,7 +148,7 @@ public class TestForm extends WebappTestCase {
         // Ensure the Text field is filled
         assertEquals(forms[0].getParameterValue("text"), "@startuml\nBob -> Alice : hello\n@enduml");
         // Ensure the URL field is filled
-        assertEquals(forms[1].getParameterValue("url"), getServerUrl() + "img/" + TestUtils.SEQBOB);
+        assertEquals(forms[1].getParameterValue("url"), getServerUrl() + "png/" + TestUtils.SEQBOB);
         // Ensure the the image is present
         assertEquals(1, response.getImages().length);
     }
diff --git a/src/test/java/net/sourceforge/plantuml/servlet/TestImage.java b/src/test/java/net/sourceforge/plantuml/servlet/TestImage.java
index b0f6cd5..6463d07 100644
--- a/src/test/java/net/sourceforge/plantuml/servlet/TestImage.java
+++ b/src/test/java/net/sourceforge/plantuml/servlet/TestImage.java
@@ -17,7 +17,7 @@ public class TestImage extends WebappTestCase {
      */
     public void testVersionImage() throws Exception {
         WebConversation conversation = new WebConversation();
-        WebRequest request = new GetMethodWebRequest(getServerUrl() + "img/" + TestUtils.VERSION);
+        WebRequest request = new GetMethodWebRequest(getServerUrl() + "png/" + TestUtils.VERSION);
         WebResponse response = conversation.getResource(request);
         // Analyze response
         // Verifies the Content-Type header
@@ -44,7 +44,7 @@ public class TestImage extends WebappTestCase {
     public void testDiagramHttpHeader() throws Exception {
         WebConversation conversation = new WebConversation();
         // Bob -> Alice : hello
-        WebRequest request = new GetMethodWebRequest(getServerUrl() + "img/" + TestUtils.SEQBOB);
+        WebRequest request = new GetMethodWebRequest(getServerUrl() + "png/" + TestUtils.SEQBOB);
         WebResponse response = conversation.getResource(request);
         // Analyze response
         // Verifies the Content-Type header
@@ -63,4 +63,22 @@ public class TestImage extends WebappTestCase {
             ; // Do nothing
         }
     }
+    
+    /**
+     * Verifies that the HTTP header of a diagram incites the browser to cache it.
+     */
+    public void testOldImgURL() throws Exception {
+        WebConversation conversation = new WebConversation();
+        // Bob -> Alice : hello
+        WebRequest request = new GetMethodWebRequest(getServerUrl() + "img/" + TestUtils.SEQBOB);
+        WebResponse response = conversation.getResource(request);
+        // Analyze response
+        // Verifies the Content-Type header
+        assertEquals("Response content type is not PNG", "image/png", response.getContentType());
+        // Consume the response
+        InputStream responseStream = response.getInputStream();
+        while (responseStream.read() != -1) {
+            ; // Do nothing
+        }
+    }    
 }