diff --git a/shell/tokenize.mu b/shell/tokenize.mu
index d40ca2bb..d591646c 100644
--- a/shell/tokenize.mu
+++ b/shell/tokenize.mu
@@ -557,13 +557,15 @@ fn quote-token? _in: (addr cell) -> _/eax: boolean {
 fn open-paren-token? _in: (addr cell) -> _/eax: boolean {
   var in/eax: (addr cell) <- copy _in
   var in-data-ah/eax: (addr handle stream byte) <- get in, text-data
-  var in-data/eax: (addr stream byte) <- lookup *in-data-ah
+  var _in-data/eax: (addr stream byte) <- lookup *in-data-ah
+  var in-data/ecx: (addr stream byte) <- copy _in-data
   rewind-stream in-data
   var g/eax: grapheme <- read-grapheme in-data
   compare g, 0x28/open-paren
   {
     break-if-!=
-    return 1/true
+    var result/eax: boolean <- stream-empty? in-data
+    return result
   }
   return 0/false
 }
@@ -571,13 +573,15 @@ fn open-paren-token? _in: (addr cell) -> _/eax: boolean {
 fn close-paren-token? _in: (addr cell) -> _/eax: boolean {
   var in/eax: (addr cell) <- copy _in
   var in-data-ah/eax: (addr handle stream byte) <- get in, text-data
-  var in-data/eax: (addr stream byte) <- lookup *in-data-ah
+  var _in-data/eax: (addr stream byte) <- lookup *in-data-ah
+  var in-data/ecx: (addr stream byte) <- copy _in-data
   rewind-stream in-data
   var g/eax: grapheme <- read-grapheme in-data
-  compare g, 0x29/open-paren
+  compare g, 0x29/close-paren
   {
     break-if-!=
-    return 1/true
+    var result/eax: boolean <- stream-empty? in-data
+    return result
   }
   return 0/false
 }