diff --git a/core/io/streams/duplex/duplex-docs.factor b/core/io/streams/duplex/duplex-docs.factor
index 6a956c6694..a745d07f4b 100755
--- a/core/io/streams/duplex/duplex-docs.factor
+++ b/core/io/streams/duplex/duplex-docs.factor
@@ -16,7 +16,5 @@ HELP: <duplex-stream>
 { $values { "in" "an input stream" } { "out" "an output stream" } { "stream" " a duplex stream" } }
 { $description "Creates a duplex stream. Writing to a duplex stream will write to " { $snippet "out" } ", and reading from a duplex stream will read from " { $snippet "in" } ". Closing a duplex stream closes both the input and output streams." } ;
 
-HELP: check-closed
-{ $values { "stream" "a duplex stream" } }
-{ $description "Throws a " { $link check-closed } " error if the stream has already been closed." }
+HELP: stream-closed-twice
 { $error-description "This error is thrown when performing an I/O operation on a " { $link duplex-stream } " which has been closed with " { $link dispose } "." } ;
diff --git a/core/io/streams/duplex/duplex.factor b/core/io/streams/duplex/duplex.factor
index 574735a9c5..008416ab66 100755
--- a/core/io/streams/duplex/duplex.factor
+++ b/core/io/streams/duplex/duplex.factor
@@ -11,10 +11,10 @@ TUPLE: duplex-stream in out closed ;
 : <duplex-stream> ( in out -- stream )
     f duplex-stream construct-boa ;
 
-<PRIVATE
-
 ERROR: stream-closed-twice ;
 
+<PRIVATE
+
 : check-closed ( stream -- stream )
     dup closed>> [ stream-closed-twice ] when ; inline