diff --git a/internal/syscallcompat/quirks_linux.go b/internal/syscallcompat/quirks_linux.go
index ffdbfab..262e48f 100644
--- a/internal/syscallcompat/quirks_linux.go
+++ b/internal/syscallcompat/quirks_linux.go
@@ -11,11 +11,6 @@ import (
 //
 // Tested by tests/root_test.TestBtrfsQuirks
 func DetectQuirks(cipherdir string) (q uint64) {
-	const (
-		// From Linux' man statfs
-		BTRFS_SUPER_MAGIC = 0x9123683e
-	)
-
 	var st unix.Statfs_t
 	err := unix.Statfs(cipherdir, &st)
 	if err != nil {
@@ -27,7 +22,7 @@ func DetectQuirks(cipherdir string) (q uint64) {
 	// and slow ( https://github.com/rfjakob/gocryptfs/issues/63 ).
 	//
 	// Cast to uint32 avoids compile error on arm: "constant 2435016766 overflows int32"
-	if uint32(st.Type) == BTRFS_SUPER_MAGIC {
+	if uint32(st.Type) == unix.BTRFS_SUPER_MAGIC {
 		logQuirk("Btrfs detected, forcing -noprealloc. See https://github.com/rfjakob/gocryptfs/issues/395 for why.")
 		q |= QuirkBrokenFalloc
 	}