diff --git a/kcmkwin/kwinrules/rulesmodel.cpp b/kcmkwin/kwinrules/rulesmodel.cpp
index e4ba5087aa..0044837f1a 100644
--- a/kcmkwin/kwinrules/rulesmodel.cpp
+++ b/kcmkwin/kwinrules/rulesmodel.cpp
@@ -233,7 +233,6 @@ QString RulesModel::warningMessage() const
     return QString();
 }
 
-
 bool RulesModel::wmclassWarning() const
 {
     const bool no_wmclass = !m_rules["wmclass"]->isEnabled()
@@ -625,11 +624,6 @@ void RulesModel::populateRuleList()
 const QHash<QString, QString> RulesModel::x11PropertyHash()
 {
     static const auto propertyToRule = QHash<QString, QString> {
-        /* The original detection dialog allows to choose depending on "Match complete window class":
-         *     if Match Complete == false: wmclass = "resourceClass"
-         *     if Match Complete == true:  wmclass = "resourceName" + " " + "resourceClass"
-         */
-        { "resourceName",       "wmclass"       },
         { "caption",            "title"         },
         { "role",               "windowrole"    },
         { "clientMachine",      "clientmachine" },
@@ -668,6 +662,13 @@ void RulesModel::setWindowProperties(const QVariantMap &info, bool forceValue)
     }
     m_rules["types"]->setSuggestedValue(1 << window_type, forceValue);
 
+    const QString wmsimpleclass = info.value("resourceClass").toString();
+    const QString wmcompleteclass = QStringLiteral("%1 %2").arg(info.value("resourceName").toString(),
+                                                                info.value("resourceClass").toString());
+    const bool isComplete = m_rules.value("wmclasscomplete")->value().toBool();
+
+    m_rules["wmclass"]->setSuggestedValue(isComplete ? wmcompleteclass : wmsimpleclass, forceValue);
+
     const auto ruleForProperty = x11PropertyHash();
     for (QString &property : info.keys()) {
         if (!ruleForProperty.contains(property)) {