diff --git a/ChangeLog b/ChangeLog
index 56246e6e9..aaa4d5503 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,7 @@
 
 	* Source/win32/GSFileHandleWin32.m: Ignore extraneous write events.
 	* Source/NSString.m: Don't insert native path separators by default.
+	* Source/NSProcessInfo.m: Report correct operating system on windows.
 
 2006-02-07  Richard Frith-Macdonald <rfm@gnu.org>
 
diff --git a/Headers/Foundation/NSProcessInfo.h b/Headers/Foundation/NSProcessInfo.h
index 4f918fe1a..5e672a3c4 100644
--- a/Headers/Foundation/NSProcessInfo.h
+++ b/Headers/Foundation/NSProcessInfo.h
@@ -51,7 +51,8 @@ enum {
   NSOSF1OperatingSystem,
   NSGNULinuxOperatingSystem = 100,
   NSBSDOperatingSystem,
-  NSBeOperatingSystem
+  NSBeOperatingSystem,
+  NSCygwinOperatingSystem
 };
 #endif
 
diff --git a/Source/NSProcessInfo.m b/Source/NSProcessInfo.m
index 91d3c7afa..182c48b6e 100644
--- a/Source/NSProcessInfo.m
+++ b/Source/NSProcessInfo.m
@@ -936,6 +936,7 @@ int main(int argc, char *argv[], char *env[])
  * <item>NSOSF1OperatingSystem - probably never to be implemented</item>
  * <item>NSGNULinuxOperatingSystem - the GNUstep 'standard'</item>
  * <item>NSBSDOperatingSystem - BSD derived operating systems</item>
+ * <item>NSCygwinOperatingSystem - cygwin unix-like environment</item>
  * </list>
  */
 - (unsigned int) operatingSystem
@@ -950,13 +951,13 @@ int main(int argc, char *argv[], char *env[])
         {
 	  os = NSGNULinuxOperatingSystem;
 	}
-      else if ([n isEqualToString: @"mingw"] == YES)
+      else if ([n hasPrefix: @"mingw"] == YES)
         {
 	  os = NSWindowsNTOperatingSystem;
 	}
       else if ([n isEqualToString: @"cygwin"] == YES)
         {
-	  os = NSWindowsNTOperatingSystem;
+	  os = NSCygwinOperatingSystem;
 	}
       else if ([n hasPrefix: @"bsd"] == YES)
         {