diff --git a/pymbolic/mapper/stringifier.py b/pymbolic/mapper/stringifier.py
index 754e9665f54cfdcb733b81f6cb5b8a0fbeb116ff..b681c8ea21746c2e4fb869c63fd70c48b49852eb 100644
--- a/pymbolic/mapper/stringifier.py
+++ b/pymbolic/mapper/stringifier.py
@@ -47,11 +47,9 @@ class StringifyMapper(pymbolic.mapper.RecursiveMapper):
     def map_constant(self, expr, enclosing_prec):
         result = self.constant_mapper(expr)
 
-        if (
-                (isinstance(expr, (int, float, long)) and expr < 0) 
-                or 
-                (isinstance(expr, complex) and expr.imag and expr.real)
-                ) and (enclosing_prec > PREC_SUM):
+        if not (result.startswith("(") and result.endswith(")")) \
+                and ("-" in result or "+" in result) \
+                and (enclosing_prec > PREC_SUM):
             return self.parenthesize(result)
         else:
             return result