diff --git a/plugins/filetemplates/templateselectionpage.cpp b/plugins/filetemplates/templateselectionpage.cpp
--- a/plugins/filetemplates/templateselectionpage.cpp
+++ b/plugins/filetemplates/templateselectionpage.cpp
@@ -97,6 +97,16 @@
     }
 
     TemplatePreviewRenderer renderer;
+    // set default option values
+    if (fileTemplate.hasCustomOptions()) {
+        QVariantHash extraVars;
+        for (const auto& option : fileTemplate.customOptions(&renderer)) {
+            for (const auto& entry : option) {
+                extraVars[entry.name] = entry.value;
+            }
+        }
+        renderer.addVariables(extraVars);
+    }
     renderer.setEmptyLinesPolicy(TemplateRenderer::TrimEmptyLines);
 
     QTemporaryDir dir;