diff --git a/schmidl_cox.hh b/schmidl_cox.hh
index 429a6df..78816fd 100644
--- a/schmidl_cox.hh
+++ b/schmidl_cox.hh
@@ -117,7 +117,7 @@ public:
 			return false;
 
 		int pos_err = std::nearbyint(arg(tmp1[shift]) * symbol_len / Const::TwoPi());
-		if (abs(pos_err) > guard_len / 2)
+		if (abs(pos_err) > guard_len)
 			return false;
 		symbol_pos -= pos_err;