diff --git a/core/utils.py b/core/utils.py
index 9a1498e..ee2d422 100644
--- a/core/utils.py
+++ b/core/utils.py
@@ -23,7 +23,7 @@ def detect_fps(input_path):
     output = os.popen(f'ffprobe -v error -select_streams v -of default=noprint_wrappers=1:nokey=1 -show_entries stream=r_frame_rate "{input_path}"').read()
     if "/" in output:
         try:
-            return int(output.split(os.sep)[0]) // int(output.split(os.sep)[1]), output.removesuffix('\n')
+            return int(output.split("/")[0]) // int(output.split("/")[1]), output.removesuffix('\n')
         except:
             pass
     return 30, 30
diff --git a/run.py b/run.py
index 7eb9fed..42a892a 100755
--- a/run.py
+++ b/run.py
@@ -145,11 +145,11 @@ def select_target():
 
 
 def toggle_fps_limit():
-    args['keep_fps'] = limit_fps.get() != True
+    args['keep_fps'] = int(limit_fps.get() != True)
 
 
 def toggle_keep_frames():
-    args['keep_frames'] = keep_frames.get() != True
+    args['keep_frames'] = int(keep_frames.get())
 
 
 def save_file():
@@ -252,13 +252,12 @@ if __name__ == "__main__":
     target_button.place(x=360,y=320,width=180,height=80)
 
     # FPS limit checkbox
-    limit_fps = tk.IntVar()
+    limit_fps = tk.IntVar(None, not args['keep_fps'])
     fps_checkbox = tk.Checkbutton(window, relief="groove", activebackground="#2d3436", activeforeground="#74b9ff", selectcolor="black", text="Limit FPS to 30", fg="#dfe6e9", borderwidth=0, highlightthickness=0, bg="#2d3436", variable=limit_fps, command=toggle_fps_limit)
     fps_checkbox.place(x=30,y=500,width=240,height=31)
-    fps_checkbox.select()
 
     # Keep frames checkbox
-    keep_frames = tk.IntVar()
+    keep_frames = tk.IntVar(None, args['keep_frames'])
     frames_checkbox = tk.Checkbutton(window, relief="groove", activebackground="#2d3436", activeforeground="#74b9ff", selectcolor="black", text="Keep frames dir", fg="#dfe6e9", borderwidth=0, highlightthickness=0, bg="#2d3436", variable=keep_frames, command=toggle_keep_frames)
     frames_checkbox.place(x=37,y=450,width=240,height=31)