diff --git a/pkg/blobstore/grpcservers/byte_stream_server.go b/pkg/blobstore/grpcservers/byte_stream_server.go
index 8e377bb7..a80baa72 100644
--- a/pkg/blobstore/grpcservers/byte_stream_server.go
+++ b/pkg/blobstore/grpcservers/byte_stream_server.go
@@ -9,6 +9,7 @@ import (
 	"github.com/buildbarn/bb-storage/pkg/blobstore"
 	"github.com/buildbarn/bb-storage/pkg/blobstore/buffer"
 	"github.com/buildbarn/bb-storage/pkg/digest"
+	"github.com/buildbarn/bb-storage/pkg/util"
 	bb_zstd "github.com/buildbarn/bb-storage/pkg/zstd"
 
 	"google.golang.org/genproto/googleapis/bytestream"
@@ -220,9 +221,8 @@ func (s *byteStreamServer) writeZstd(stream bytestream.ByteStream_WriteServer, r
 
 	zstdReader, err := bb_zstd.NewReadCloser(ctx, s.zstdPool, streamReader)
 	if err != nil {
-		return status.Errorf(codes.ResourceExhausted, "Failed to acquire ZSTD decoder: %v", err)
+		return util.StatusWrap(err, "Failed to acquire ZSTD decoder")
 	}
-	defer zstdReader.Close()
 
 	if err := s.blobAccess.Put(
 		ctx,
diff --git a/pkg/zstd/metrics_pool.go b/pkg/zstd/metrics_pool.go
index 08e204f5..6b3c8d0d 100644
--- a/pkg/zstd/metrics_pool.go
+++ b/pkg/zstd/metrics_pool.go
@@ -126,7 +126,11 @@ type metricsEncoder struct {
 }
 
 func (e *metricsEncoder) Close() error {
+	if e.Encoder == nil {
+		return nil
+	}
 	err := e.Encoder.Close()
+	e.Encoder = nil
 	e.releases.Inc()
 	return err
 }
@@ -137,6 +141,10 @@ type metricsDecoder struct {
 }
 
 func (d *metricsDecoder) Close() {
+	if d.Decoder == nil {
+		return
+	}
 	d.Decoder.Close()
+	d.Decoder = nil
 	d.releases.Inc()
 }