diff --git a/repository/Zinc-Character-Encoding-Core.package/ZnUTF8Encoder.class/instance/ensureAtBeginOfCodePointOnStream..st b/repository/Zinc-Character-Encoding-Core.package/ZnUTF8Encoder.class/instance/ensureAtBeginOfCodePointOnStream..st
index 5a8ff945..3f5685fa 100644
--- a/repository/Zinc-Character-Encoding-Core.package/ZnUTF8Encoder.class/instance/ensureAtBeginOfCodePointOnStream..st
+++ b/repository/Zinc-Character-Encoding-Core.package/ZnUTF8Encoder.class/instance/ensureAtBeginOfCodePointOnStream..st
@@ -4,6 +4,8 @@ ensureAtBeginOfCodePointOnStream: stream
 	if not move further backwards. This is necessary when a position in the binary stream is set,
 	not knowing if that position is on a proper encoded character boundary."
 
+	"If we are at end-of-stream, we can't be in the middle of an encoded codepoint
+	(unless that codepoint is incomplete and thus invalid, which we won't worry about)"
+	stream atEnd ifTrue: [ ^ self ].
 	"Back up until we are not longer on a continuation byte but on a leading byte"
-
 	[ (stream peek bitAnd: 2r11000000) == 2r10000000 ] whileTrue: [ stream back ]
\ No newline at end of file
diff --git a/repository/Zinc-Character-Encoding-Core.package/monticello.meta/categories.st b/repository/Zinc-Character-Encoding-Core.package/monticello.meta/categories.st
index 2cb3537b..f2721d0c 100644
--- a/repository/Zinc-Character-Encoding-Core.package/monticello.meta/categories.st
+++ b/repository/Zinc-Character-Encoding-Core.package/monticello.meta/categories.st
@@ -1 +1 @@
-SystemOrganization addCategory: #'Zinc-Character-Encoding-Core'!
+self packageOrganizer ensurePackage: #'Zinc-Character-Encoding-Core' withTags: #()!
diff --git a/repository/Zinc-Character-Encoding-Tests.package/ZnCharacterStreamTest.class/instance/testUTF8ReadStreamPositioning.st b/repository/Zinc-Character-Encoding-Tests.package/ZnCharacterStreamTest.class/instance/testUTF8ReadStreamPositioning.st
index 9cc9d865..14378fea 100644
--- a/repository/Zinc-Character-Encoding-Tests.package/ZnCharacterStreamTest.class/instance/testUTF8ReadStreamPositioning.st
+++ b/repository/Zinc-Character-Encoding-Tests.package/ZnCharacterStreamTest.class/instance/testUTF8ReadStreamPositioning.st
@@ -17,4 +17,6 @@ testUTF8ReadStreamPositioning
 	stream position: 5.
 	self assert: stream next equals: $v.
 	stream position: 6.
-	self assert: stream next equals: $e
\ No newline at end of file
+	self assert: stream next equals: $e.
+	stream position: 7.
+	self assert: stream atEnd.
\ No newline at end of file
diff --git a/repository/Zinc-Character-Encoding-Tests.package/monticello.meta/categories.st b/repository/Zinc-Character-Encoding-Tests.package/monticello.meta/categories.st
index d2931a20..099ac033 100644
--- a/repository/Zinc-Character-Encoding-Tests.package/monticello.meta/categories.st
+++ b/repository/Zinc-Character-Encoding-Tests.package/monticello.meta/categories.st
@@ -1 +1 @@
-SystemOrganization addCategory: #'Zinc-Character-Encoding-Tests'!
+self packageOrganizer ensurePackage: #'Zinc-Character-Encoding-Tests' withTags: #()!