diff --git a/src/lerobot/configs/video.py b/src/lerobot/configs/video.py
index 20e46a387..4b956f30e 100644
--- a/src/lerobot/configs/video.py
+++ b/src/lerobot/configs/video.py
@@ -226,24 +226,24 @@ class VideoEncoderConfig:
             if encoder_threads is not None:
                 svtav1_parts.append(f"lp={encoder_threads}")
             if svtav1_parts:
-                opts["svtav1-params"] = ":".join(svtav1_parts)
+                set_if("svtav1-params", ":".join(svtav1_parts))
         elif self.vcodec in ("h264", "hevc"):
             set_if("crf", self.crf)
             set_if("preset", self.preset)
             if self.fast_decode:
-                opts["tune"] = "fastdecode"
+                set_if("tune", "fastdecode")
             set_if("threads", encoder_threads)
         elif self.vcodec == "libaom-av1":
             set_if("crf", self.crf)
             set_if("preset", self.preset)
             if encoder_threads is not None:
-                opts["threads"] = encoder_threads
-                opts["row-mt"] = 1
+                set_if("threads", encoder_threads)
+                set_if("row-mt", 1)
         elif self.vcodec in ("h264_videotoolbox", "hevc_videotoolbox"):
             if self.crf is not None:
-                opts["q:v"] = max(1, min(100, 100 - self.crf * 2))
+                set_if("q:v", max(1, min(100, 100 - self.crf * 2)))
         elif self.vcodec in ("h264_nvenc", "hevc_nvenc"):
-            opts["rc"] = 0
+            set_if("rc", 0)
             set_if("qp", self.crf)
             set_if("preset", self.preset)
         elif self.vcodec == "h264_vaapi":
diff --git a/tests/datasets/test_video_encoding.py b/tests/datasets/test_video_encoding.py
index 80819d665..4bfb65ee1 100644
--- a/tests/datasets/test_video_encoding.py
+++ b/tests/datasets/test_video_encoding.py
@@ -345,7 +345,9 @@ class TestExtraOptions:
         opts = cfg.get_codec_options()
         assert opts["qp"] == 20
         assert isinstance(opts["qp"], int)
-        assert cfg.get_codec_options(as_strings=True)["qp"] == "20"
+        str_opts = cfg.get_codec_options(as_strings=True)
+        assert str_opts["qp"] == "20"
+        assert all(isinstance(v, str) for v in str_opts.values())
 
     @require_libsvtav1
     def test_structured_fields_win_on_collision(self):