diff --git a/data/model/image.py b/data/model/image.py
index b9954b593..f3291a242 100644
--- a/data/model/image.py
+++ b/data/model/image.py
@@ -476,14 +476,14 @@ def get_secscan_candidates(engine_version, batch_size):
                            ImageStorage.uploading == False)
                     .limit(batch_size*10))
 
-  images = (Image
-            .select(Image, ImageStorage)
-            .join(ImageStorage)
-            .where(Image.id << candidates)
-            .order_by(db_random_func())
-            .limit(batch_size))
-
-  rimages.extend(images)
+  if len(candidates) > 0:
+    images = (Image
+              .select(Image, ImageStorage)
+              .join(ImageStorage)
+              .where(Image.id << candidates)
+              .order_by(db_random_func())
+              .limit(batch_size))
+    rimages.extend(images)
 
   # Collect the images with analyzed parents.
   candidates = list(Image
@@ -497,17 +497,17 @@ def get_secscan_candidates(engine_version, batch_size):
                            ImageStorage.uploading == False)
                     .limit(batch_size*10))
 
-  images = (Image
-            .select(Image, ImageStorage, Parent, ParentImageStorage)
-            .join(Parent, on=(Image.parent == Parent.id))
-            .join(ParentImageStorage, on=(ParentImageStorage.id == Parent.storage))
-            .switch(Image)
-            .join(ImageStorage)
-            .where(Image.id << candidates)
-            .order_by(db_random_func())
-            .limit(batch_size))
-
-  rimages.extend(images)
+  if len(candidates) > 0:
+    images = (Image
+              .select(Image, ImageStorage, Parent, ParentImageStorage)
+              .join(Parent, on=(Image.parent == Parent.id))
+              .join(ParentImageStorage, on=(ParentImageStorage.id == Parent.storage))
+              .switch(Image)
+              .join(ImageStorage)
+              .where(Image.id << candidates)
+              .order_by(db_random_func())
+              .limit(batch_size))
+    rimages.extend(images)
 
   # Shuffle the images, otherwise the images without parents will always be on the top
   random.shuffle(rimages)