diff --git a/nats-streaming-server.go b/nats-streaming-server.go
index 4c682071..5edb296a 100644
--- a/nats-streaming-server.go
+++ b/nats-streaming-server.go
@@ -133,7 +133,7 @@ func parseFlags() (*stand.Options, *natsd.Options) {
 	flag.Int64Var(&stanOpts.FileStoreOpts.CompactMinFileSize, "file_compact_min_size", stores.DefaultFileStoreOptions.CompactMinFileSize, "Minimum file size for compaction")
 	flag.IntVar(&stanOpts.FileStoreOpts.BufferSize, "file_buffer_size", stores.DefaultFileStoreOptions.BufferSize, "File buffer size (in bytes)")
 	flag.BoolVar(&stanOpts.FileStoreOpts.DoCRC, "file_crc", stores.DefaultFileStoreOptions.DoCRC, "Enable file CRC-32 checksum")
-	flag.IntVar(&stanOpts.FileStoreOpts.CRCPolynomial, "file_crc_poly", stores.DefaultFileStoreOptions.CRCPolynomial, "Polynomial used to make the table used for CRC-32 checksum")
+	flag.Int64Var(&stanOpts.FileStoreOpts.CRCPolynomial, "file_crc_poly", stores.DefaultFileStoreOptions.CRCPolynomial, "Polynomial used to make the table used for CRC-32 checksum")
 	flag.IntVar(&stanOpts.IOBatchSize, "io_batch_size", stand.DefaultIOBatchSize, "# of message to batch in flushing io")
 	flag.Int64Var(&stanOpts.IOSleepTime, "io_sleep_time", stand.DefaultIOSleepTime, "duration the server waits for more messages (in micro-seconds, 0 to disable)")
 	// NATS options
diff --git a/stores/filestore.go b/stores/filestore.go
index fe3c85d4..11e96ed7 100644
--- a/stores/filestore.go
+++ b/stores/filestore.go
@@ -74,7 +74,7 @@ type FileStoreOptions struct {
 	DoCRC bool
 
 	// CRCPoly is a polynomial used to make the table used in CRC computation.
-	CRCPolynomial int
+	CRCPolynomial int64
 }
 
 // DefaultFileStoreOptions defines the default options for a File Store.
@@ -85,7 +85,7 @@ var DefaultFileStoreOptions = FileStoreOptions{
 	CompactFragmentation: 50,
 	CompactMinFileSize:   1024 * 1024,
 	DoCRC:                true,
-	CRCPolynomial:        crc32.IEEE,
+	CRCPolynomial:        int64(crc32.IEEE),
 }
 
 // BufferSize is a FileStore option that sets the size of the buffer used
@@ -148,7 +148,7 @@ func DoCRC(enableCRC bool) FileStoreOption {
 // CRCPolynomial is a FileStore option that defines the polynomial to use to create
 // the table used for CRC-32 Checksum.
 // See https://golang.org/pkg/hash/crc32/#MakeTable
-func CRCPolynomial(polynomial int) FileStoreOption {
+func CRCPolynomial(polynomial int64) FileStoreOption {
 	return func(o *FileStoreOptions) error {
 		o.CRCPolynomial = polynomial
 		return nil
@@ -412,7 +412,7 @@ func NewFileStore(rootDir string, limits *ChannelLimits, options ...FileStoreOpt
 	// Convert the compact interval in time.Duration
 	fs.compactItvl = time.Duration(fs.opts.CompactInterval) * time.Second
 	// Create the table using polynomial in options
-	if fs.opts.CRCPolynomial == crc32.IEEE {
+	if fs.opts.CRCPolynomial == int64(crc32.IEEE) {
 		fs.crcTable = crc32.IEEETable
 	} else {
 		fs.crcTable = crc32.MakeTable(uint32(fs.opts.CRCPolynomial))
diff --git a/stores/filestore_test.go b/stores/filestore_test.go
index 4c72f90c..51d092ae 100644
--- a/stores/filestore_test.go
+++ b/stores/filestore_test.go
@@ -222,7 +222,7 @@ func TestFSOptions(t *testing.T) {
 		CompactInterval:      60,
 		CompactMinFileSize:   1024 * 1024,
 		DoCRC:                false,
-		CRCPolynomial:        crc32.Castagnoli,
+		CRCPolynomial:        int64(crc32.Castagnoli),
 	}
 	// Create the file with custom options
 	fs, _, err := NewFileStore(defaultDataStore, &testDefaultChannelLimits,
@@ -232,7 +232,7 @@ func TestFSOptions(t *testing.T) {
 		CompactInterval(expected.CompactInterval),
 		CompactMinFileSize(expected.CompactMinFileSize),
 		DoCRC(expected.DoCRC),
-		CRCPolynomial(int(expected.CRCPolynomial)))
+		CRCPolynomial(expected.CRCPolynomial))
 	if err != nil {
 		t.Fatalf("Unexpected error on file store create: %v", err)
 	}