diff --git a/mxcubeweb/core/adapter/detector_adapter.py b/mxcubeweb/core/adapter/detector_adapter.py
index 23ffc7b4e..9de507267 100644
--- a/mxcubeweb/core/adapter/detector_adapter.py
+++ b/mxcubeweb/core/adapter/detector_adapter.py
@@ -36,7 +36,7 @@ def _state_change(self, *args, **kwargs):
     def state(self):
         return self._ho.get_state().name.upper()
 
-    def display_image(self, path: str, img_num) -> dict:
+    def display_image(self, path: str, img_num: int) -> dict:
         """Notify ADXV and/or Braggy of the image to display."""
         res = {"image_url": ""}
 
diff --git a/mxcubeweb/core/server/resource_handler.py b/mxcubeweb/core/server/resource_handler.py
index b6c570aba..d4490c3f0 100644
--- a/mxcubeweb/core/server/resource_handler.py
+++ b/mxcubeweb/core/server/resource_handler.py
@@ -28,7 +28,10 @@ def valid_object_id(object_id: str) -> bool:
 
 
 def validate_input_str(input_string: str) -> bool:
-    """Validate that input string contains only alphanumeric characters and/or dot (.).
+    """Validate input string.
+
+    Ensure that input string contains only alphanumeric characters and/or
+    posix path characters such as dot (.), backslash (/) and dash (-).
 
     Args:
         input_string (str): The string to validate.
@@ -36,7 +39,7 @@ def validate_input_str(input_string: str) -> bool:
     Returns:
         bool: True if the string is valid, False otherwise.
     """
-    pattern = r"^[a-zA-Z0-9._]*$"
+    pattern = r"^[a-zA-Z0-9._/-]*$"
     return bool(re.match(pattern, input_string))
 
 
diff --git a/ui/src/actions/general.js b/ui/src/actions/general.js
index ed95d8d5a..8f63db05a 100644
--- a/ui/src/actions/general.js
+++ b/ui/src/actions/general.js
@@ -42,7 +42,7 @@ export function displayImage(path, imgNum) {
       'detector',
       'detector',
       'display_image',
-      { path, imgNum },
+      { path, img_num: imgNum },
     );
     window.open(data.image_url, 'braggy');
   };