diff --git a/fs/bcachefs/bcachefs_format.h b/fs/bcachefs/bcachefs_format.h
index 90c12fe2a2cd..5d3c5b5e34af 100644
--- a/fs/bcachefs/bcachefs_format.h
+++ b/fs/bcachefs/bcachefs_format.h
@@ -1382,9 +1382,10 @@ enum btree_id {
 
 /*
  * Maximum number of btrees that we will _ever_ have under the current scheme,
- * where we refer to them with bitfields
+ * where we refer to them with 64 bit bitfields - and we also need a bit for
+ * the interior btree node type:
  */
-#define BTREE_ID_NR_MAX		64
+#define BTREE_ID_NR_MAX		63
 
 static inline bool btree_id_is_alloc(enum btree_id id)
 {
diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index d63db4fefe73..87f485e9c552 100644
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -761,13 +761,13 @@ static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 
 static inline bool btree_node_type_is_extents(enum btree_node_type type)
 {
-	const unsigned mask = 0
+	const u64 mask = 0
 #define x(name, nr, flags, ...)	|((!!((flags) & BTREE_ID_EXTENTS)) << (nr + 1))
 	BCH_BTREE_IDS()
 #undef x
 	;
 
-	return (1U << type) & mask;
+	return BIT_ULL(type) & mask;
 }
 
 static inline bool btree_id_is_extents(enum btree_id btree)
@@ -777,35 +777,35 @@ static inline bool btree_id_is_extents(enum btree_id btree)
 
 static inline bool btree_type_has_snapshots(enum btree_id id)
 {
-	const unsigned mask = 0
+	const u64 mask = 0
 #define x(name, nr, flags, ...)	|((!!((flags) & BTREE_ID_SNAPSHOTS)) << nr)
 	BCH_BTREE_IDS()
 #undef x
 	;
 
-	return (1U << id) & mask;
+	return BIT_ULL(id) & mask;
 }
 
 static inline bool btree_type_has_snapshot_field(enum btree_id id)
 {
-	const unsigned mask = 0
+	const u64 mask = 0
 #define x(name, nr, flags, ...)	|((!!((flags) & (BTREE_ID_SNAPSHOT_FIELD|BTREE_ID_SNAPSHOTS))) << nr)
 	BCH_BTREE_IDS()
 #undef x
 	;
 
-	return (1U << id) & mask;
+	return BIT_ULL(id) & mask;
 }
 
 static inline bool btree_type_has_ptrs(enum btree_id id)
 {
-	const unsigned mask = 0
+	const u64 mask = 0
 #define x(name, nr, flags, ...)	|((!!((flags) & BTREE_ID_DATA)) << nr)
 	BCH_BTREE_IDS()
 #undef x
 	;
 
-	return (1U << id) & mask;
+	return BIT_ULL(id) & mask;
 }
 
 struct btree_root {