diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 2bdf72f2e..b3ed9ffe6 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -43,6 +43,7 @@ Christoph Wilhelms
 Christophe Labouisse
 Christopher A. Longo
 Christopher Charlier
+Clemens Hammacher
 Conor MacNeill
 Craeg Strong
 Craig Cottingham
diff --git a/WHATSNEW b/WHATSNEW
index 9c3925c94..59938a3bb 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -214,6 +214,10 @@ Fixed bugs:
    the link's target.
    Bugzilla Report 41525.
 
+ * when checking whether a jar is signed, <signjar> ignored the
+   sigfile attribute.
+   Bugzilla Report 44805.
+
 Other changes:
 --------------
 
diff --git a/contributors.xml b/contributors.xml
index f78b0322d..4f9d3993d 100644
--- a/contributors.xml
+++ b/contributors.xml
@@ -194,6 +194,10 @@
     <first>Christopher</first>
     <last>Charlier</last>
   </name>
+  <name>
+    <first>Clemens</first>
+    <last>Hammacher</last>
+  </name>
   <name>
     <first>Conor</first>
     <last>MacNeill</last>
diff --git a/src/main/org/apache/tools/ant/taskdefs/SignJar.java b/src/main/org/apache/tools/ant/taskdefs/SignJar.java
index 2b1aa8e6e..ed62f3a0e 100644
--- a/src/main/org/apache/tools/ant/taskdefs/SignJar.java
+++ b/src/main/org/apache/tools/ant/taskdefs/SignJar.java
@@ -474,7 +474,7 @@ public class SignJar extends AbstractJarSignerTask {
 
     /**
      * test for a file being signed, by looking for a signature in the META-INF
-     * directory with our alias.
+     * directory with our alias/sigfile.
      *
      * @param file the file to be checked
      * @return true if the file is signed
@@ -482,7 +482,7 @@ public class SignJar extends AbstractJarSignerTask {
      */
     protected boolean isSigned(File file) {
         try {
-            return IsSigned.isSigned(file, alias);
+            return IsSigned.isSigned(file, sigfile == null ? alias : sigfile);
         } catch (IOException e) {
             //just log this
             log(e.toString(), Project.MSG_VERBOSE);
diff --git a/src/tests/junit/org/apache/tools/ant/taskdefs/SignJarTest.java b/src/tests/junit/org/apache/tools/ant/taskdefs/SignJarTest.java
index a232d6aa1..ece8eeadb 100644
--- a/src/tests/junit/org/apache/tools/ant/taskdefs/SignJarTest.java
+++ b/src/tests/junit/org/apache/tools/ant/taskdefs/SignJarTest.java
@@ -18,6 +18,7 @@
 
 package org.apache.tools.ant.taskdefs;
 
+import java.io.File;
 import org.apache.tools.ant.BuildFileTest;
 import org.apache.tools.ant.util.JavaEnvUtils;
 
@@ -56,6 +57,27 @@ public class SignJarTest extends BuildFileTest {
 
     public void testSigFile() {
         executeTarget("sigfile");
+        SignJarChild sj = new SignJarChild();
+        sj.setAlias("testonly");
+        sj.setKeystore("testkeystore");
+        sj.setStorepass("apacheant");
+        File jar = new File(getProject().getProperty("test.jar"));
+        sj.setJar(jar);
+        assertFalse("mustn't find signature without sigfile attribute",
+                    sj.isSigned());
+        sj.setSigfile("TEST");
+        assertTrue("must find signature with sigfile attribute",
+                   sj.isSigned());
+    }
+
+    /**
+     * subclass in order to get access to protected isSigned method if
+     * tests and task come from different classloaders.
+     */
+    private static class SignJarChild extends SignJar {
+        public boolean isSigned() {
+            return isSigned(jar);
+        }
     }
 
     public void testMaxMemory() {