diff --git a/questionable/withoutresult.nim b/questionable/withoutresult.nim
index 17cd333..786cc49 100644
--- a/questionable/withoutresult.nim
+++ b/questionable/withoutresult.nim
@@ -2,13 +2,14 @@ import std/macros
 import ./without
 import ./private/binderror
 
+const symbolKinds = {nnkSym, nnkOpenSymChoice, nnkClosedSymChoice}
+const identKinds = {nnkIdent} + symbolKinds
+
 proc undoSymbolResolution(expression, ident: NimNode): NimNode =
   ## Finds symbols in the expression that match the `ident` and replaces them
   ## with `ident`, effectively undoing any symbol resolution that happened
   ## before.
 
-  const symbolKinds = {nnkSym, nnkOpenSymChoice, nnkClosedSymChoice}
-
   if expression.kind in symbolKinds and eqIdent($expression, $ident):
     return ident
 
@@ -22,6 +23,9 @@ macro without*(condition, errorname, body: untyped): untyped =
   ## Used to place guards that ensure that a Result contains a value.
   ## Exposes error when Result does not contain a value.
 
+  if errorname.kind notin identKinds:
+    error("expected an identifier, got " & errorname.repr, errorname)
+
   let errorIdent = ident $errorname
 
   # Nim's early symbol resolution might have picked up a symbol with the