diff --git a/map/put.xml b/map/put.xml
index df381827..edd86fbe 100644
--- a/map/put.xml
+++ b/map/put.xml
@@ -290,8 +290,9 @@
     </test-case>
     
     <test-case name="map-put-026">
-        <description>The new entry has the type annotation of the new key</description>
+        <description>The new entry may change the type annotation of the new key</description>
         <created by="Michael Kay, Saxonica" on="2025-01-29"/>
+        <modified by="Christian Gruen" on="2025-01-30" change="Implementation-dependent key handling"/>
         <environment ref="map"/>
         <test>
             {"x":5, "y":6} 
@@ -299,19 +300,28 @@
             => map:put(xs:NCName("y"), 60)
             => map:keys()</test>
         <result>
-            <assert-type>xs:NCName+</assert-type>
+            <any-of>
+                <assert-type>xs:string+</assert-type>
+                <assert-type>xs:NCName+</assert-type>
+            </any-of>
         </result>
     </test-case>
     
     <test-case name="map-put-027">
-        <description>The new entry has the type annotation of the new key</description>
+        <description>The new entry may change the type annotation of the new key</description>
         <created by="Michael Kay, Saxonica" on="2025-01-29"/>
+        <modified by="Christian Gruen" on="2025-01-30" change="Implementation-dependent key handling"/>
         <environment ref="map"/>
         <test>
-            ( {"x":5, "y":6} 
-               => map:put(xs:NCName("x"), true()) 
-               => map:put(xs:NCName("y"), (false(), false()))
-            ) instance of map(xs:NCName, xs:boolean+)
+        let $map := (
+          {"x":5, "y":6} 
+          => map:put(xs:NCName("x"), true()) 
+          => map:put(xs:NCName("y"), (false(), false()))
+        )
+        return (
+          $map instance of map(xs:NCName, xs:boolean+) or
+          $map instance of map(xs:string, xs:boolean+)
+        )
         </test>
         <result>
             <assert-true/>