diff --git a/OMEdit/OMEditLIB/Element/ElementProperties.cpp b/OMEdit/OMEditLIB/Element/ElementProperties.cpp
index adb9281a005..5591de532e9 100644
--- a/OMEdit/OMEditLIB/Element/ElementProperties.cpp
+++ b/OMEdit/OMEditLIB/Element/ElementProperties.cpp
@@ -772,7 +772,7 @@ void Parameter::createValueWidget()
     case Parameter::Normal:
     default:
       mpValueTextBox = new QLineEdit;
-      connect(mpValueTextBox, SIGNAL(textEdited(QString)), SLOT(valueTextBoxEdited(QString)));
+      mpValueTextBox->installEventFilter(this);
       break;
   }
 }
@@ -1049,16 +1049,6 @@ void Parameter::valueCheckBoxChanged(bool toggle)
   updateValueBinding(FlatModelica::Expression(toggle));
 }
 
-/*!
- * \brief Parameter::valueTextBoxEdited
- * This slot is only called when user manually edits the text.\n
- * \param text
- */
-void Parameter::valueTextBoxEdited(const QString &text)
-{
-  enableDisableUnitComboBox(text);
-}
-
 void Parameter::showFixedMenu()
 {
   // create a menu
@@ -1115,6 +1105,22 @@ void Parameter::inheritedFixedClicked()
   mpFixedCheckBox->setTickState(true, mpFixedCheckBox->getInheritedValue());
 }
 
+/*!
+ * \brief Parameter::eventFilter
+ * Handles the FocusOut event of value textbox.
+ * \param pWatched
+ * \param pEvent
+ * \return
+ */
+bool Parameter::eventFilter(QObject *pWatched, QEvent *pEvent)
+{
+  if (mpValueTextBox == pWatched && pEvent->type() == QEvent::FocusOut) {
+    enableDisableUnitComboBox(mpValueTextBox->text());
+  }
+
+  return QObject::eventFilter(pWatched, pEvent);
+}
+
 /*!
   \class GroupBox
   \brief Creates a group for parameters.
diff --git a/OMEdit/OMEditLIB/Element/ElementProperties.h b/OMEdit/OMEditLIB/Element/ElementProperties.h
index 2559b4676d7..52e95db2b88 100644
--- a/OMEdit/OMEditLIB/Element/ElementProperties.h
+++ b/OMEdit/OMEditLIB/Element/ElementProperties.h
@@ -178,11 +178,13 @@ public slots:
   void unitComboBoxChanged(int index);
   void valueComboBoxChanged(int index);
   void valueCheckBoxChanged(bool toggle);
-  void valueTextBoxEdited(const QString &text);
   void showFixedMenu();
   void trueFixedClicked();
   void falseFixedClicked();
   void inheritedFixedClicked();
+  // QObject interface
+public:
+  virtual bool eventFilter(QObject *pWatched, QEvent *pEvent) override;
 };
 
 class GroupBox : public QGroupBox
diff --git a/OMEdit/OMEditLIB/Util/Utilities.cpp b/OMEdit/OMEditLIB/Util/Utilities.cpp
index 315ce53e6cd..2ed89f56d30 100644
--- a/OMEdit/OMEditLIB/Util/Utilities.cpp
+++ b/OMEdit/OMEditLIB/Util/Utilities.cpp
@@ -640,23 +640,11 @@ qreal Utilities::convertUnit(qreal value, qreal offset, qreal scaleFactor)
 bool Utilities::isValueLiteralConstant(QString value)
 {
   /* Issue #11795. Allow setting negative values for parameters.
-   * In future we should use proper regular expressions for this. Maybe when we switch to Qt 6.
+   * Issue #11840. Allow setting array of values.
+   * The following regular expression allows decimal values and array of decimal values. The values can be negative.
    */
-  if (value.compare(QStringLiteral("-")) == 0) {
-    return true;
-  }
-
-  bool ok = true;
-  value.toDouble(&ok);
-  if (ok) {
-    return true;
-  }
-
-  QStringList valuesArray = StringHandler::removeFirstLastCurlBrackets(value).split(",");
-  foreach (QString valueElement, valuesArray) {
-    valueElement.toDouble(&ok);
-  }
-  return ok;
+  QRegExp rx("\\{?\\s*-?\\d+(\\.\\d+)?(?:\\s*,\\s*-?\\d+(\\.\\d+)?)*\\s*\\}?");
+  return rx.exactMatch(value);
 }
 
 /*!