diff --git a/src/Lepiter-Snippet-Example/LeExampleSnippet.class.st b/src/Lepiter-Snippet-Example/LeExampleSnippet.class.st
index 795f3e8d0..a2c397d38 100644
--- a/src/Lepiter-Snippet-Example/LeExampleSnippet.class.st
+++ b/src/Lepiter-Snippet-Example/LeExampleSnippet.class.st
@@ -128,6 +128,17 @@ LeExampleSnippet >> contentAsString [
 	^ '{{gtExample:', self asAnnotationString, '}}'
 ]
 
+{ #category : #'api - accessing' }
+LeExampleSnippet >> copyFrom: aLeExampleSnippet [
+	self codeExpanded: aLeExampleSnippet codeExpanded.
+	self exampleBehaviorName: aLeExampleSnippet exampleBehaviorName.
+	self exampleSelector: aLeExampleSnippet exampleSelector.
+	self noCode: aLeExampleSnippet noCode.
+	self previewExpanded: aLeExampleSnippet previewExpanded.
+	self previewHeight: aLeExampleSnippet previewHeight.
+	self previewShowSelector: aLeExampleSnippet previewShowSelector.
+]
+
 { #category : #initialization }
 LeExampleSnippet >> defaultCodeExpanded [
 	^ true
diff --git a/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationValidator.class.st b/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationValidator.class.st
new file mode 100644
index 000000000..ec574f9e1
--- /dev/null
+++ b/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationValidator.class.st
@@ -0,0 +1,44 @@
+Class {
+	#name : #LeExampleSnippetAnnotationValidator,
+	#superclass : #Object,
+	#traits : 'TLeAnnotationParseNodeVisitor',
+	#classTraits : 'TLeAnnotationParseNodeVisitor classTrait',
+	#instVars : [
+		'isValid'
+	],
+	#category : #'Lepiter-Snippet-Example-Snippet'
+}
+
+{ #category : #initialization }
+LeExampleSnippetAnnotationValidator >> initialize [
+	super initialize.
+	
+	isValid := true
+]
+
+{ #category : #accessing }
+LeExampleSnippetAnnotationValidator >> isValid [
+	^ isValid
+]
+
+{ #category : #accessing }
+LeExampleSnippetAnnotationValidator >> validate: anAst [
+	isValid := true.
+	self accept: anAst.
+	^ self isValid
+]
+
+{ #category : #visiting }
+LeExampleSnippetAnnotationValidator >> visitCodeExpandedArgument: aCodeExpandedArgument [
+	isValid := isValid and: [ aCodeExpandedArgument hasValidBooleanValue ]
+]
+
+{ #category : #generated }
+LeExampleSnippetAnnotationValidator >> visitNoCodeArgument: aNoCodeArgument [
+	isValid := isValid and: [ aNoCodeArgument hasValidBooleanValue ]
+]
+
+{ #category : #generated }
+LeExampleSnippetAnnotationValidator >> visitPreviewExpandedArgument: aPreviewExpandedArgument [
+	isValid := isValid and: [ aPreviewExpandedArgument hasValidBooleanValue ]
+]
diff --git a/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationVisitor.class.st b/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationVisitor.class.st
index acfe37715..45bab58c5 100644
--- a/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationVisitor.class.st
+++ b/src/Lepiter-Snippet-Example/LeExampleSnippetAnnotationVisitor.class.st
@@ -51,7 +51,7 @@ LeExampleSnippetAnnotationVisitor >> visitNoCodeArgument: aNoCodeArgument [
 LeExampleSnippetAnnotationVisitor >> visitPreviewExpandedArgument: aPreviewExpandedArgument [
 	aPreviewExpandedArgument hasValidBooleanValue
 		ifFalse: [ ^ self ].
-
+	
 	self exampleSnippet previewExpanded: aPreviewExpandedArgument booleanValue
 ]
 
diff --git a/src/Lepiter-Snippet-Example/LeExampleSnippetViewModel.class.st b/src/Lepiter-Snippet-Example/LeExampleSnippetViewModel.class.st
index cdfe5ca78..f6702725e 100644
--- a/src/Lepiter-Snippet-Example/LeExampleSnippetViewModel.class.st
+++ b/src/Lepiter-Snippet-Example/LeExampleSnippetViewModel.class.st
@@ -200,7 +200,7 @@ LeExampleSnippetViewModel >> notifyAnnotationCoderViewModelChanged [
 
 { #category : #'private - event handling' }
 LeExampleSnippetViewModel >> onAnnotationAstChanged: anAstChangedAnnouncement [
-	| anAst |
+	| anAst aNewSnippet |
 	
 	anAst := anAstChangedAnnouncement ast.
 	anAst
@@ -208,15 +208,27 @@ LeExampleSnippetViewModel >> onAnnotationAstChanged: anAstChangedAnnouncement [
 		andTokensDo: [ :eachToken | ]
 		includeErrors: true.
 	
+	aNewSnippet := LeExampleSnippet new.
+	
+	"this will modify the properties of a default snippet while making sure that removing properties falls back to default"
+	LeExampleSnippetAnnotationVisitor new
+		exampleSnippet: aNewSnippet;
+		accept: anAst.
+	
+	"if properties did not change, do nothing"
+	(self snippetModel similarTo: aNewSnippet)
+		ifTrue: [ ^ self ].
+	
 	"it is possible that multiple parameters were changes as part of the ast update.
 	we should queue them up and request annotation update only once at the very end"
 	self optionAt: #doNotUpdateText put: true.
 	[
-		LeExampleSnippetAnnotationVisitor new
-			exampleSnippet: self;
-			accept: anAst.
+		self snippetModel copyFrom: aNewSnippet
 	] ensure: [ self optionAt: #doNotUpdateText put: false ].
-
+	
+	(LeExampleSnippetAnnotationValidator new validate: anAst)
+		ifFalse: [ ^ self ].
+	
 	self requestUpdateAnnotationText
 ]