diff --git a/ghc/driver/ghc.lprl b/ghc/driver/ghc.lprl
index ea1a7e3dd7a798612947ac569a5ca979f9f5b6ef..e68881d54eda0c2ad52b11317891035753774a84 100644
--- a/ghc/driver/ghc.lprl
+++ b/ghc/driver/ghc.lprl
@@ -158,7 +158,14 @@ $SIG{'QUIT'} = 'quit_upon_signal';
 			   : "$TopPwd/${CURRENT_DIR}" );
 
 if ( $ENV{'TMPDIR'} ) { # where to make tmp file names
-    $Tmp_prefix = ($ENV{'TMPDIR'} . "/ghc$$");
+    # Try to find a $Tmp_prefix which isn't being used...
+    $tmp = $$;
+    do {
+      $Tmp_prefix = ($ENV{'TMPDIR'} . "/ghc$tmp");
+      $tmp++;
+    } while ( -e "$Tmp_prefix.hc" ||
+	      -e "$Tmp_Prefix.s"  || 
+	      -e "$Tmp_Prefix.hi" );
 } else {
     print STDERR "TMPDIR has not been set to anything useful!\n" if (${TMPDIR} eq '');
     $Tmp_prefix ="${TMPDIR}/ghc$$"; # TMPDIR set via Makefile when booting..