diff --git a/src/Zinc-Character-Encoding-Core/ZnEncodedReadStream.class.st b/src/Zinc-Character-Encoding-Core/ZnEncodedReadStream.class.st
index 1c9c2dba97e..19eb1e30675 100644
--- a/src/Zinc-Character-Encoding-Core/ZnEncodedReadStream.class.st
+++ b/src/Zinc-Character-Encoding-Core/ZnEncodedReadStream.class.st
@@ -34,11 +34,6 @@ ZnEncodedReadStream >> contents [
 	^ self upToEnd
 ]
 
-{ #category : 'testing' }
-ZnEncodedReadStream >> isBinary [
-	^ false
-]
-
 { #category : 'testing' }
 ZnEncodedReadStream >> isReadOnly [
 
diff --git a/src/Zinc-Character-Encoding-Core/ZnEncodedStream.class.st b/src/Zinc-Character-Encoding-Core/ZnEncodedStream.class.st
index 780805f70e0..fa2f56a3466 100644
--- a/src/Zinc-Character-Encoding-Core/ZnEncodedStream.class.st
+++ b/src/Zinc-Character-Encoding-Core/ZnEncodedStream.class.st
@@ -64,6 +64,11 @@ ZnEncodedStream >> flush [
 	^ stream flush
 ]
 
+{ #category : 'testing' }
+ZnEncodedStream >> isBinary [
+	^ false
+]
+
 { #category : 'testing' }
 ZnEncodedStream >> isStream [
   ^ true
diff --git a/src/Zinc-Character-Encoding-Core/ZnEncodedWriteStream.class.st b/src/Zinc-Character-Encoding-Core/ZnEncodedWriteStream.class.st
index 09d55477531..d629dfeb61a 100644
--- a/src/Zinc-Character-Encoding-Core/ZnEncodedWriteStream.class.st
+++ b/src/Zinc-Character-Encoding-Core/ZnEncodedWriteStream.class.st
@@ -26,11 +26,6 @@ ZnEncodedWriteStream >> flush [
 	stream flush
 ]
 
-{ #category : 'testing' }
-ZnEncodedWriteStream >> isBinary [
-	^ false
-]
-
 { #category : 'accessing' }
 ZnEncodedWriteStream >> next: count putAll: collection [
 	self