diff --git a/src/main/java/de/mattv/fileserver/data/DataValidator.java b/src/main/java/de/mattv/fileserver/data/DataValidator.java
index 79c7c1a..29475ec 100644
--- a/src/main/java/de/mattv/fileserver/data/DataValidator.java
+++ b/src/main/java/de/mattv/fileserver/data/DataValidator.java
@@ -63,8 +63,12 @@ public class DataValidator {
                 errors++;
             }
             if (node.hasPreview && !node.previewFile.exists()) {
-                log.warn("Missing preview file for node {}, regenerating", node.id);
+                log.warn("Regenerated missing preview file for node {}", node.id);
                 node.createThumbnail();
+            } else if (!node.hasPreview) {
+                node.createThumbnail();
+                if (node.hasPreview)
+                    log.warn("Regenerated missing preview file for node {}, which was not marked with preview", node.id);
             }
             if (!node.file.exists()) {
                 if (node.size == 0) {