diff --git a/src/fns.c b/src/fns.c
index ab4fc237630..e7dc8dc1bb7 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -3124,12 +3124,12 @@ value_cmp (Lisp_Object a, Lisp_Object b, int maxdepth)
 		  return pa < pb ? -1 : pa > pb;
 		}
 
-#ifndef MSDOS
+#ifdef subprocesses
 	      case PVEC_PROCESS:
 		a = Fprocess_name (a);
 		b = Fprocess_name (b);
 		goto tail_recurse;
-#endif /* MSDOS */
+#endif /* subprocesses */
 
 	      case PVEC_BUFFER:
 		{