diff --git a/libwvdrmengine/cdm/core/src/crypto_session.cpp b/libwvdrmengine/cdm/core/src/crypto_session.cpp
index f7f2b9e5..939af6dd 100644
--- a/libwvdrmengine/cdm/core/src/crypto_session.cpp
+++ b/libwvdrmengine/cdm/core/src/crypto_session.cpp
@@ -161,6 +161,7 @@ void AdvanceDestBuffer(OEMCrypto_DestBufferDesc* dest_buffer, size_t bytes) {
   switch (dest_buffer->type) {
     case OEMCrypto_BufferType_Clear:
       dest_buffer->buffer.clear.clear_buffer += bytes;
+      dest_buffer->buffer.clear.clear_buffer_length -= bytes;
       return;
 
     case OEMCrypto_BufferType_Secure:
@@ -3253,11 +3254,6 @@ OEMCryptoResult CryptoSession::DecryptSample(
         }
 
         fake_sample.buffers.input_data_length = length;
-        if (fake_sample.buffers.output_descriptor.type ==
-            OEMCrypto_BufferType_Clear) {
-          fake_sample.buffers.output_descriptor.buffer.clear
-              .clear_buffer_length = length;
-        }
         fake_sample.subsamples = &clear_subsample;
         fake_sample.subsamples_length = 1;
 
@@ -3285,11 +3281,6 @@ OEMCryptoResult CryptoSession::DecryptSample(
         }
 
         fake_sample.buffers.input_data_length = length;
-        if (fake_sample.buffers.output_descriptor.type ==
-            OEMCrypto_BufferType_Clear) {
-          fake_sample.buffers.output_descriptor.buffer.clear
-              .clear_buffer_length = length;
-        }
         fake_sample.subsamples = &encrypted_subsample;
         fake_sample.subsamples_length = 1;
 
@@ -3382,10 +3373,6 @@ OEMCryptoResult CryptoSession::LegacyCopyBufferInChunks(
     // Calculate the size of the next chunk.
     const size_t chunk_size = std::min(remaining_input_data, max_chunk_size);
 
-    if (output_descriptor.type == OEMCrypto_BufferType_Clear) {
-      output_descriptor.buffer.clear.clear_buffer_length = chunk_size;
-    }
-
     // Re-add "last subsample" flag if this is the last subsample.
     if (chunk_size == remaining_input_data) {
       subsample_flags |= OEMCrypto_LastSubsample;
@@ -3433,11 +3420,6 @@ OEMCryptoResult CryptoSession::LegacyDecryptInChunks(
     // Calculate the size of the next chunk.
     const size_t chunk_size = std::min(remaining_input_data, max_chunk_size);
     fake_sample.buffers.input_data_length = chunk_size;
-    if (fake_sample.buffers.output_descriptor.type ==
-        OEMCrypto_BufferType_Clear) {
-      fake_sample.buffers.output_descriptor.buffer.clear.clear_buffer_length =
-          chunk_size;
-    }
     if (is_protected) {
       fake_subsample.num_bytes_encrypted = chunk_size;
     } else {
diff --git a/libwvdrmengine/oemcrypto/test/oec_decrypt_fallback_chain.cpp b/libwvdrmengine/oemcrypto/test/oec_decrypt_fallback_chain.cpp
index fe303fc6..6cb7aac0 100644
--- a/libwvdrmengine/oemcrypto/test/oec_decrypt_fallback_chain.cpp
+++ b/libwvdrmengine/oemcrypto/test/oec_decrypt_fallback_chain.cpp
@@ -17,6 +17,7 @@ void advance_dest_buffer(OEMCrypto_DestBufferDesc* dest_buffer, size_t bytes) {
   switch (dest_buffer->type) {
     case OEMCrypto_BufferType_Clear:
       dest_buffer->buffer.clear.clear_buffer += bytes;
+      dest_buffer->buffer.clear.clear_buffer_length -= bytes;
       break;
 
     case OEMCrypto_BufferType_Secure:
@@ -98,11 +99,6 @@ OEMCryptoResult DecryptFallbackChain::DecryptSample(
     const size_t length =
         subsample.num_bytes_clear + subsample.num_bytes_encrypted;
     fake_sample.buffers.input_data_length = length;
-    if (fake_sample.buffers.output_descriptor.type ==
-        OEMCrypto_BufferType_Clear) {
-      fake_sample.buffers.output_descriptor.buffer.clear.clear_buffer_length =
-          length;
-    }
     fake_sample.subsamples = &subsample;
     fake_sample.subsamples_length = 1;
 
@@ -148,11 +144,6 @@ OEMCryptoResult DecryptFallbackChain::DecryptSubsample(
 
   if (subsample.num_bytes_clear > 0) {
     fake_sample.buffers.input_data_length = subsample.num_bytes_clear;
-    if (fake_sample.buffers.output_descriptor.type ==
-        OEMCrypto_BufferType_Clear) {
-      fake_sample.buffers.output_descriptor.buffer.clear.clear_buffer_length =
-          subsample.num_bytes_clear;
-    }
     fake_subsample.num_bytes_clear = subsample.num_bytes_clear;
     fake_subsample.num_bytes_encrypted = 0;
     fake_subsample.block_offset = 0;
@@ -176,11 +167,6 @@ OEMCryptoResult DecryptFallbackChain::DecryptSubsample(
 
   if (subsample.num_bytes_encrypted > 0) {
     fake_sample.buffers.input_data_length = subsample.num_bytes_encrypted;
-    if (fake_sample.buffers.output_descriptor.type ==
-        OEMCrypto_BufferType_Clear) {
-      fake_sample.buffers.output_descriptor.buffer.clear.clear_buffer_length =
-          subsample.num_bytes_encrypted;
-    }
     fake_subsample.num_bytes_clear = 0;
     fake_subsample.num_bytes_encrypted = subsample.num_bytes_encrypted;
     fake_subsample.block_offset = subsample.block_offset;