diff --git a/crates/pf-encode/src/enc/linux/mod.rs b/crates/pf-encode/src/enc/linux/mod.rs
index 69014d0f..9fc2fc0c 100644
--- a/crates/pf-encode/src/enc/linux/mod.rs
+++ b/crates/pf-encode/src/enc/linux/mod.rs
@@ -468,7 +468,15 @@ impl NvencEncoder {
             // sessions) and reopen this session without intra-refresh; any other failure — and
             // any failure when IR wasn't requested — propagates untouched (the bitrate probe
             // keys on EINVAL, which must not trip the latch).
-            Err(e) if intra_refresh && format!("{e:#}").contains("Function not implemented") => {
+            Err(e)
+                if intra_refresh
+                    && matches!(
+                        e,
+                        ffmpeg::Error::Other {
+                            errno: ffmpeg::util::error::ENOSYS
+                        }
+                    ) =>
+            {
                 tracing::warn!(
                     encoder = name,
                     "NVENC intra-refresh not supported by this GPU — falling back to IDR-only \
diff --git a/crates/pf-encode/src/lib.rs b/crates/pf-encode/src/lib.rs
index 4a20be95..ad25d6e4 100644
--- a/crates/pf-encode/src/lib.rs
+++ b/crates/pf-encode/src/lib.rs
@@ -897,13 +897,29 @@ fn open_nvenc_probed(
             }
             // EINVAL = above this GPU's level ceiling → step down. Any other failure (no GPU,
             // bad mode, OOM) is real — surface it rather than masking it with bitrate retries.
-            Err(e) if format!("{e:#}").contains("Invalid argument") => last = Some(e),
+            Err(e) if nvenc_open_einval(&e) => last = Some(e),
             Err(e) => return Err(e),
         }
     }
     Err(last.unwrap_or_else(|| anyhow::anyhow!("encoder open failed at every probed bitrate")))
 }
 
+/// Whether a libav NVENC open failed with EINVAL — the "bitrate above this GPU's level ceiling"
+/// signal [`open_nvenc_probed`]'s ladder steps down on. Typed: the root `ffmpeg::Error` survives
+/// the `anyhow` context chain, so match it there instead of substring-matching the English
+/// strerror rendering of the whole chain — which also fired on any OTHER wrapped EINVAL (e.g. a
+/// CUDA-context errno) and steered the ladder on failures that have nothing to do with bitrate.
+#[cfg(target_os = "linux")]
+fn nvenc_open_einval(e: &anyhow::Error) -> bool {
+    use ffmpeg_next as ffmpeg;
+    matches!(
+        e.downcast_ref::<ffmpeg::Error>(),
+        Some(ffmpeg::Error::Other {
+            errno: ffmpeg::util::error::EINVAL
+        })
+    )
+}
+
 /// Whether the direct-SDK NVENC path is active. **Default ON** — on-glass validated 2026-07-12:
 /// real RFI landed 73/73 as clean P-frame recovery anchors (never IDR) on an RTX host with a real
 /// Steam Deck client (design/linux-direct-nvenc.md §9). `PUNKTFUNK_NVENC_DIRECT=0` (also `false`/