diff --git a/src/qtism/runtime/expressions/MapResponseProcessor.php b/src/qtism/runtime/expressions/MapResponseProcessor.php
index ab9a1851c..cba91e9d8 100644
--- a/src/qtism/runtime/expressions/MapResponseProcessor.php
+++ b/src/qtism/runtime/expressions/MapResponseProcessor.php
@@ -117,13 +117,13 @@ public function process()
                             for ($i = 0; $i < count($mapEntries); $i++) {
 
                                 $mapKey = $rawMapKey = $mapEntries[$i]->getMapKey();
-
+                                $processedVal = null;
                                 if ($val instanceof QtiString && $mapEntries[$i]->isCaseSensitive() === false) {
-                                    $val = mb_strtolower($val->getValue(), 'UTF-8');
+                                    $processedVal = mb_strtolower($val->getValue(), 'UTF-8');
                                     $mapKey = mb_strtolower($mapKey, 'UTF-8');
                                 }
 
-                                if (($val instanceof Comparable && $val->equals($mapKey) === true) || $val === $mapKey) {
+                                if (($val instanceof Comparable && $val->equals($mapKey) === true) || $processedVal === $mapKey) {
                                     if (in_array($rawMapKey, $mapped, true) === false) {
                                         $result += $mapEntries[$i]->getMappedValue();
                                         $mapped[] = $rawMapKey;
diff --git a/test/qtismtest/runtime/expressions/MapResponseProcessorTest.php b/test/qtismtest/runtime/expressions/MapResponseProcessorTest.php
index 466bf8a7b..0312df455 100644
--- a/test/qtismtest/runtime/expressions/MapResponseProcessorTest.php
+++ b/test/qtismtest/runtime/expressions/MapResponseProcessorTest.php
@@ -143,8 +143,8 @@ public function testMultipleCardinalityIdentifierToFloat() {
 	                <value>Choice7</value>
 	            </correctResponse>
 	            <mapping>
-	                <mapEntry mapKey="Choice1" mappedValue="2"/>
-	                <mapEntry mapKey="Choice6" mappedValue="20"/>
+	                <mapEntry mapKey="Choice1" mappedValue="2" caseSensitive="false"/>
+	                <mapEntry mapKey="Choice6" mappedValue="20" caseSensitive="false"/>
                     <mapEntry mapKey="Choice9" mappedValue="20"/>
 	                <mapEntry mapKey="Choice2" mappedValue="-20"/>
 	                <mapEntry mapKey="Choice3" mappedValue="-20"/>