diff --git a/docs/manual/CoreTasks/conditions.html b/docs/manual/CoreTasks/conditions.html
index ac66f63cc..059dc44a1 100644
--- a/docs/manual/CoreTasks/conditions.html
+++ b/docs/manual/CoreTasks/conditions.html
@@ -114,7 +114,7 @@ the tests succeed.
   <li>os/2 (for OS/2)</li>
   <li>tandem (for HP's NonStop Kernel - formerly Tandem)</li>
   <li>win9x for Microsoft Windows 95 and 98, ME and CE</li>
-  <li>nt for Microsoft Windows NT-based systems, including Windows 2000, XP and
+  <li>winnt for Microsoft Windows NT-based systems, including Windows 2000, XP and
       successors</li>
   <li>z/os for z/OS and OS/390</li>
   <li>os/400 for OS/400</li>
diff --git a/src/etc/testcases/taskdefs/exec/exec.xml b/src/etc/testcases/taskdefs/exec/exec.xml
index 3255c7396..c7c3eb78d 100644
--- a/src/etc/testcases/taskdefs/exec/exec.xml
+++ b/src/etc/testcases/taskdefs/exec/exec.xml
@@ -344,7 +344,7 @@
       </exec>
       <exec executable="time"
         failonerror="true"
-        osFamily="nt">
+        osFamily="winnt">
         <arg value="/t" />
       </exec>
     </target>    
diff --git a/src/main/org/apache/tools/ant/taskdefs/condition/Os.java b/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
index de3fa67c8..4ec31981d 100644
--- a/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
+++ b/src/main/org/apache/tools/ant/taskdefs/condition/Os.java
@@ -63,7 +63,7 @@ public class Os implements Condition {
     /**
      * OS family that can be tested for. {@value}
      */
-    public static final String FAMILY_NT = "nt";
+    public static final String FAMILY_NT = "winnt";
     /**
      * OS family that can be tested for. {@value}
      */