diff --git a/inout/CHANGELOG.md b/inout/CHANGELOG.md
index d95336f6..9fb3ac46 100644
--- a/inout/CHANGELOG.md
+++ b/inout/CHANGELOG.md
@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.2.5 (2026-10-16)
+### Fixed
+- Return `PadError` from `InOutBufReserved::into_padded_blocks`
+  for incorrect `Padding` implementations  ([#1562])
+
+[#1562]: https://github.com/RustCrypto/utils/pull/1562
+
 ## 0.2.4 (2026-10-16)
 ### Fixed
 - Output buffer length check in `InOutBufReserved::into_padded_blocks` ([#1559])
diff --git a/inout/src/reserved.rs b/inout/src/reserved.rs
index 101b29f0..d165fadc 100644
--- a/inout/src/reserved.rs
+++ b/inout/src/reserved.rs
@@ -168,7 +168,6 @@ impl<'inp, 'out> InOutBufReserved<'inp, 'out, u8> {
     /// # Errors
     /// If the padding is invalid
     #[inline(always)]
-    #[allow(clippy::missing_panics_doc)]
     pub fn into_padded_blocks<P, BS>(self) -> Result<PaddedInOutBuf<'inp, 'out, BS>, PadError>
     where
         P: Padding,
@@ -197,8 +196,13 @@ impl<'inp, 'out> InOutBufReserved<'inp, 'out, u8> {
             PaddedData::Error => return Err(PadError),
         };
 
-        // This invariant must hold for all valid padding implementations.
-        debug_assert_eq!(blocks.len(), self.in_len / BS::USIZE);
+        // These invariants must hold for all valid padding implementations.
+        if blocks.as_ptr().cast() != self.in_ptr {
+            return Err(PadError);
+        }
+        if blocks.len() != self.in_len / BS::USIZE {
+            return Err(PadError);
+        }
 
         Ok(PaddedInOutBuf {
             in_ptr: blocks.as_ptr(),