diff --git a/live_tracker.go b/live_tracker.go
index e2c4057..e62dc59 100644
--- a/live_tracker.go
+++ b/live_tracker.go
@@ -229,6 +229,12 @@ func (l *liveTracker) innerAddNinjaStringDeps(str *ninjaString) error {
 	return nil
 }
 
+func (l *liveTracker) Eval(n *ninjaString) (string, error) {
+	l.Lock()
+	defer l.Unlock()
+	return n.Eval(l.variables)
+}
+
 func (l *liveTracker) RemoveVariableIfLive(v Variable) bool {
 	l.Lock()
 	defer l.Unlock()
diff --git a/singleton_ctx.go b/singleton_ctx.go
index 95c29c4..176aa25 100644
--- a/singleton_ctx.go
+++ b/singleton_ctx.go
@@ -289,7 +289,7 @@ func (s *singletonContext) Eval(pctx PackageContext, str string) (string, error)
 		return "", err
 	}
 
-	return ninjaStr.Eval(s.globals.variables)
+	return s.globals.Eval(ninjaStr)
 }
 
 func (s *singletonContext) RequireNinjaVersion(major, minor, micro int) {