diff --git a/tag.go b/tag.go
index 4debdb7..1bea2b7 100644
--- a/tag.go
+++ b/tag.go
@@ -21,26 +21,26 @@ func (t *Tag) AsObject() *Object {
 	return &t.Object
 }
 
-func (t Tag) Message() string {
+func (t *Tag) Message() string {
 	ret := C.GoString(C.git_tag_message(t.cast_ptr))
 	runtime.KeepAlive(t)
 	return ret
 }
 
-func (t Tag) Name() string {
+func (t *Tag) Name() string {
 	ret := C.GoString(C.git_tag_name(t.cast_ptr))
 	runtime.KeepAlive(t)
 	return ret
 }
 
-func (t Tag) Tagger() *Signature {
+func (t *Tag) Tagger() *Signature {
 	cast_ptr := C.git_tag_tagger(t.cast_ptr)
 	ret := newSignatureFromC(cast_ptr)
 	runtime.KeepAlive(t)
 	return ret
 }
 
-func (t Tag) Target() *Object {
+func (t *Tag) Target() *Object {
 	var ptr *C.git_object
 	ret := C.git_tag_target(&ptr, t.cast_ptr)
 	runtime.KeepAlive(t)
@@ -51,13 +51,13 @@ func (t Tag) Target() *Object {
 	return allocObject(ptr, t.repo)
 }
 
-func (t Tag) TargetId() *Oid {
+func (t *Tag) TargetId() *Oid {
 	ret := newOidFromC(C.git_tag_target_id(t.cast_ptr))
 	runtime.KeepAlive(t)
 	return ret
 }
 
-func (t Tag) TargetType() ObjectType {
+func (t *Tag) TargetType() ObjectType {
 	ret := ObjectType(C.git_tag_target_type(t.cast_ptr))
 	runtime.KeepAlive(t)
 	return ret
diff --git a/tree.go b/tree.go
index 02507d2..b309193 100644
--- a/tree.go
+++ b/tree.go
@@ -47,7 +47,7 @@ func newTreeEntry(entry *C.git_tree_entry) *TreeEntry {
 	}
 }
 
-func (t Tree) EntryByName(filename string) *TreeEntry {
+func (t *Tree) EntryByName(filename string) *TreeEntry {
 	cname := C.CString(filename)
 	defer C.free(unsafe.Pointer(cname))
 
@@ -67,7 +67,7 @@ func (t Tree) EntryByName(filename string) *TreeEntry {
 // free it, but you must not use it after the Tree is freed.
 //
 // Warning: this must examine every entry in the tree, so it is not fast.
-func (t Tree) EntryById(id *Oid) *TreeEntry {
+func (t *Tree) EntryById(id *Oid) *TreeEntry {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()
 
@@ -84,7 +84,7 @@ func (t Tree) EntryById(id *Oid) *TreeEntry {
 
 // EntryByPath looks up an entry by its full path, recursing into
 // deeper trees if necessary (i.e. if there are slashes in the path)
-func (t Tree) EntryByPath(path string) (*TreeEntry, error) {
+func (t *Tree) EntryByPath(path string) (*TreeEntry, error) {
 	cpath := C.CString(path)
 	defer C.free(unsafe.Pointer(cpath))
 	var entry *C.git_tree_entry
@@ -102,7 +102,7 @@ func (t Tree) EntryByPath(path string) (*TreeEntry, error) {
 	return newTreeEntry(entry), nil
 }
 
-func (t Tree) EntryByIndex(index uint64) *TreeEntry {
+func (t *Tree) EntryByIndex(index uint64) *TreeEntry {
 	entry := C.git_tree_entry_byindex(t.cast_ptr, C.size_t(index))
 	if entry == nil {
 		return nil
@@ -113,7 +113,7 @@ func (t Tree) EntryByIndex(index uint64) *TreeEntry {
 	return goEntry
 }
 
-func (t Tree) EntryCount() uint64 {
+func (t *Tree) EntryCount() uint64 {
 	num := C.git_tree_entrycount(t.cast_ptr)
 	runtime.KeepAlive(t)
 	return uint64(num)
@@ -122,9 +122,8 @@ func (t Tree) EntryCount() uint64 {
 type TreeWalkCallback func(string, *TreeEntry) int
 
 //export CallbackGitTreeWalk
-func CallbackGitTreeWalk(_root *C.char, _entry unsafe.Pointer, ptr unsafe.Pointer) C.int {
+func CallbackGitTreeWalk(_root *C.char, entry *C.git_tree_entry, ptr unsafe.Pointer) C.int {
 	root := C.GoString(_root)
-	entry := (*C.git_tree_entry)(_entry)
 
 	if callback, ok := pointerHandles.Get(ptr).(TreeWalkCallback); ok {
 		return C.int(callback(root, newTreeEntry(entry)))
@@ -133,7 +132,7 @@ func CallbackGitTreeWalk(_root *C.char, _entry unsafe.Pointer, ptr unsafe.Pointe
 	}
 }
 
-func (t Tree) Walk(callback TreeWalkCallback) error {
+func (t *Tree) Walk(callback TreeWalkCallback) error {
 	runtime.LockOSThread()
 	defer runtime.UnlockOSThread()