diff --git a/src/PLE/Z3Node.extension.st b/src/PLE/Z3Node.extension.st
index 235e32c66..8355a2b08 100644
--- a/src/PLE/Z3Node.extension.st
+++ b/src/PLE/Z3Node.extension.st
@@ -93,7 +93,7 @@ notGuardedApps :: Expr -> [Expr]
 
 { #category : #'*PLE' }
 Z3Node >> simplify: γ in: ictx [
-	^[ :x | (x simplifyStep: γ in: ictx) simplify ] fix: self
+	^[ :x | (x simplifyStep: γ in: ictx) "simplify" ] fix: self
 ]
 
 { #category : #'*PLE' }
diff --git a/src/Z3/Z3Node.class.st b/src/Z3/Z3Node.class.st
index 16c0e400e..bc1c4341a 100644
--- a/src/Z3/Z3Node.class.st
+++ b/src/Z3/Z3Node.class.st
@@ -200,7 +200,7 @@ Z3Node >> inEnvironment: aDictionary [
 			to   add:(var coerce: val).
 		]
 	].
-	^(self substituteAll: from withoutNils with: to withoutNils) simplify
+	^(self substituteAll: from withoutNils with: to withoutNils) "simplify"
 ]
 
 { #category : #'term rewriting' }