diff --git a/server/src/video_support.rs b/server/src/video_support.rs
index 53b3bf2..3d36e41 100644
--- a/server/src/video_support.rs
+++ b/server/src/video_support.rs
@@ -342,7 +342,9 @@ mod tests {
     use super::{
         SOFTWARE_VIDEO_FALLBACK_ENV, adjust_effective_fps, contains_hevc_irap, contains_idr,
         default_eye_fps, env_u32, env_usize, is_hardware_h264_decoder, is_hardware_hevc_decoder,
-        next_local_pts, reserve_local_pts, should_send_frame, software_video_fallback_allowed,
+        next_local_pts, pick_h264_decoder, pick_hevc_decoder, require_h264_decoder,
+        require_hevc_decoder, reserve_local_pts, should_send_frame,
+        software_video_fallback_allowed,
     };
     use serial_test::serial;
     use std::sync::atomic::AtomicU64;
@@ -467,6 +469,38 @@ mod tests {
         assert!(!is_hardware_hevc_decoder("libde265dec"));
     }
 
+    #[test]
+    #[serial]
+    fn explicit_bad_decoder_overrides_fail_loudly_without_registry_assumptions() {
+        gstreamer::init().expect("initialize gstreamer registry for decoder lookup");
+
+        with_var(
+            "LESAVKA_H264_DECODER",
+            Some("definitely-not-a-decoder"),
+            || {
+                let err = require_h264_decoder().expect_err("bogus H.264 decoder should fail");
+                assert!(
+                    err.to_string().contains("not buildable"),
+                    "unexpected H.264 override error: {err:#}"
+                );
+                assert_eq!(pick_h264_decoder(), "missing-hardware-h264dec");
+            },
+        );
+
+        with_var(
+            "LESAVKA_HEVC_DECODER",
+            Some("definitely-not-a-decoder"),
+            || {
+                let err = require_hevc_decoder().expect_err("bogus HEVC decoder should fail");
+                assert!(
+                    err.to_string().contains("not buildable"),
+                    "unexpected HEVC override error: {err:#}"
+                );
+                assert_eq!(pick_hevc_decoder(), "missing-hardware-hevcdec");
+            },
+        );
+    }
+
     #[test]
     fn adjust_effective_fps_keeps_current_rate_when_no_samples() {
         assert_eq!(adjust_effective_fps(18, 12, 25, 0, 0), 18);