--- a/PositionableStream.st	Sun Sep 08 16:36:39 2019 +0200
+++ b/PositionableStream.st	Sun Sep 08 16:47:12 2019 +0200
@@ -323,7 +323,7 @@
     [pattern atEnd] whileFalse: [
         self atEnd ifTrue: [^ false].
         (self next) = (pattern next) 
-            ifTrue: [pattern position = 1 ifTrue: [startMatch := self position]]
+            ifTrue: [pattern position == 1 ifTrue: [startMatch := self position]]
             ifFalse: [
                 pattern position: 0.
                 startMatch ifNotNil: [