diff --git a/js/src/jit-test/tests/basic/bug673705.js b/js/src/jit-test/tests/basic/bug673705.js
new file mode 100644
index 00000000000..42fc30591c2
--- /dev/null
+++ b/js/src/jit-test/tests/basic/bug673705.js
@@ -0,0 +1,10 @@
+function bug673705() {
+  var x;
+  try {
+  } catch (e) {
+  } finally {
+    print(x);
+  }
+  return x;
+}
+assertEq(bug673705(), undefined);
diff --git a/js/src/jsanalyze.cpp b/js/src/jsanalyze.cpp
index e35666e5047..3f1cbcd1859 100644
--- a/js/src/jsanalyze.cpp
+++ b/js/src/jsanalyze.cpp
@@ -1247,7 +1247,7 @@ inline void
 ScriptAnalysis::ensureVariable(LifetimeVariable &var, unsigned until)
 {
     JS_ASSERT(var.lifetime);
-    JS_ASSERT(until < var.lifetime->start);
+    JS_ASSERT(until <= var.lifetime->start);
     var.lifetime->start = until;
     var.ensured = true;
 }