diff --git a/ChangeLog b/ChangeLog
index f300657f6..358ea6b49 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2006-10-17  Richard Frith-Macdonald <rfm@gnu.org>
+
+	* Source/NSPropertyList.m:
+	Fix error writing negative numbers to property list.
+
 2006-10-16  Richard Frith-Macdonald <rfm@gnu.org>
 
 	* Source/GSFFCallInvocation.m:
diff --git a/Source/NSPropertyList.m b/Source/NSPropertyList.m
index d217186cf..ac16e09ae 100644
--- a/Source/NSPropertyList.m
+++ b/Source/NSPropertyList.m
@@ -1635,7 +1635,8 @@ OAppend(id obj, NSDictionary *loc, unsigned lev, unsigned step,
 	  else if (x == NSPropertyListGNUstepFormat)
 	    {
 	      [dest appendBytes: "<*I" length: 3];
-	      PString([obj stringValue], dest);
+	      [dest appendData:
+	        [[obj stringValue] dataUsingEncoding: NSASCIIStringEncoding]];
 	      [dest appendBytes: ">" length: 1];
 	    }
 	  else
@@ -1654,7 +1655,8 @@ OAppend(id obj, NSDictionary *loc, unsigned lev, unsigned step,
 	  else if (x == NSPropertyListGNUstepFormat)
 	    {
 	      [dest appendBytes: "<*R" length: 3];
-	      PString([obj stringValue], dest);
+	      [dest appendData:
+	        [[obj stringValue] dataUsingEncoding: NSASCIIStringEncoding]];
 	      [dest appendBytes: ">" length: 1];
 	    }
 	  else