diff --git a/src/openflexure_microscope_server/things/smart_scan.py b/src/openflexure_microscope_server/things/smart_scan.py
index 20808e0f..9126b31b 100644
--- a/src/openflexure_microscope_server/things/smart_scan.py
+++ b/src/openflexure_microscope_server/things/smart_scan.py
@@ -15,6 +15,7 @@ from threading import Event
 import glob
 import json
 import piexif
+import re
 
 from labthings_fastapi.thing import Thing
 from labthings_fastapi.dependencies.metadata import GetThingStates
@@ -41,6 +42,8 @@ BackgroundDep = direct_thing_client_dependency(
     BackgroundDetectThing, "/background_detect/"
 )
 
+IMAGE_REGEX = re.compile(r"-?[0-9]+_-?[0-9]+\.jpeg$")
+
 
 def unpack_autofocus(scan_data):
     """Extract z, sharpness data from a move_and_measure call
@@ -884,7 +887,9 @@ class SmartScanThing(Thing):
             if os.path.isdir(path):
                 images_folder = os.path.join(path, IMG_DIR_NAME)
                 if os.path.isdir(images_folder):
-                    number_of_images = len(os.listdir(images_folder))
+                    folder_contents = os.listdir(images_folder)
+                    scan_images = [x for x in folder_contents if IMAGE_REGEX.search(x)]
+                    number_of_images = len(scan_images)
                 else:
                     number_of_images = 0
                 modified = max(os.stat(root).st_mtime for root, _, _ in os.walk(path))