diff --git a/impls/nim/types.nim b/impls/nim/types.nim
index a5a8ec33..5deae492 100644
--- a/impls/nim/types.nim
+++ b/impls/nim/types.nim
@@ -110,7 +110,7 @@ proc false_q*(xs: varargs[MalType]): MalType {.procvar.} =
   boolObj xs[0].kind == False
 
 proc string_q*(xs: varargs[MalType]): MalType {.procvar.} =
-  boolObj(xs[0].kind == String and xs[0].str.len > 0 and xs[0].str[0] != '\xff')
+  boolObj(xs[0].kind == String and (xs[0].str.len == 0 or xs[0].str[0] != '\xff'))
 
 proc symbol*(xs: varargs[MalType]): MalType {.procvar.} =
   symbol(xs[0].str)