diff --git a/spine-c/spine-c/include/spine/Bone.h b/spine-c/spine-c/include/spine/Bone.h
index b0b29347c..744a55628 100644
--- a/spine-c/spine-c/include/spine/Bone.h
+++ b/spine-c/spine-c/include/spine/Bone.h
@@ -48,7 +48,6 @@ struct spBone {
 	spBone **const children;
 	float x, y, rotation, scaleX, scaleY, shearX, shearY;
 	float ax, ay, arotation, ascaleX, ascaleY, ashearX, ashearY;
-	int /*bool*/ appliedValid;
 
 	float const a, b, worldX;
 	float const c, d, worldY;
@@ -68,6 +67,8 @@ SP_API void spBone_dispose(spBone *self);
 
 SP_API void spBone_setToSetupPose(spBone *self);
 
+SP_API void spBone_update(spBone *self);
+
 SP_API void spBone_updateWorldTransform(spBone *self);
 
 SP_API void spBone_updateWorldTransformWith(spBone *self, float x, float y, float rotation, float scaleX, float scaleY,
diff --git a/spine-c/spine-c/src/spine/Bone.c b/spine-c/spine-c/src/spine/Bone.c
index 34207463b..5b5cdb3e7 100644
--- a/spine-c/spine-c/src/spine/Bone.c
+++ b/spine-c/spine-c/src/spine/Bone.c
@@ -57,6 +57,10 @@ void spBone_dispose(spBone *self) {
 	FREE(self);
 }
 
+void spBone_update(spBone *self) {
+	spBone_updateWorldTransformWith(self, self->ax, self->ay, self->arotation, self->ascaleX, self->ascaleY, self->ashearX, self->ashearY);
+}
+
 void spBone_updateWorldTransform(spBone *self) {
 	spBone_updateWorldTransformWith(self, self->x, self->y, self->rotation, self->scaleX, self->scaleY, self->shearX,
 									self->shearY);
@@ -77,7 +81,6 @@ void spBone_updateWorldTransformWith(spBone *self, float x, float y, float rotat
 	self->ascaleY = scaleY;
 	self->ashearX = shearX;
 	self->ashearY = shearY;
-	self->appliedValid = 1;
 
 	if (!parent) { /* Root bone. */
 		float rotationY = rotation + 90 + shearY;
@@ -214,7 +217,6 @@ float spBone_getWorldScaleY(spBone *self) {
  * Some information is ambiguous in the world transform, such as -1,-1 scale versus 180 rotation. */
 void spBone_updateAppliedTransform(spBone *self) {
 	spBone *parent = self->parent;
-	self->appliedValid = 1;
 	if (!parent) {
 		self->ax = self->worldX;
 		self->ay = self->worldY;
@@ -289,5 +291,4 @@ void spBone_rotateWorld(spBone *self, float degrees) {
 	CONST_CAST(float, self->b) = cosine * b - sine * d;
 	CONST_CAST(float, self->c) = sine * a + cosine * c;
 	CONST_CAST(float, self->d) = sine * b + cosine * d;
-	CONST_CAST(int, self->appliedValid) = 0;
 }
diff --git a/spine-c/spine-c/src/spine/IkConstraint.c b/spine-c/spine-c/src/spine/IkConstraint.c
index 67fa335d6..92b977e8e 100644
--- a/spine-c/spine-c/src/spine/IkConstraint.c
+++ b/spine-c/spine-c/src/spine/IkConstraint.c
@@ -78,7 +78,6 @@ spIkConstraint_apply1(spBone *bone, float targetX, float targetY, int /*boolean*
 	float pa = p->a, pb = p->b, pc = p->c, pd = p->d;
 	float rotationIK = -bone->ashearX - bone->arotation;
 	float tx = 0, ty = 0, sx = 0, sy = 0, s = 0, sa = 0, sc = 0;
-	if (!bone->appliedValid) spBone_updateAppliedTransform(bone);
 
 	switch (bone->data->transformMode) {
 		case SP_TRANSFORMMODE_ONLYTRANSLATION:
@@ -139,8 +138,6 @@ spIkConstraint_apply2(spBone *parent, spBone *child, float targetX, float target
 	float id, x, y;
 	float aa, bb, ll, ta, c0, c1, c2;
 
-	if (!parent->appliedValid) spBone_updateAppliedTransform(parent);
-	if (!child->appliedValid) spBone_updateAppliedTransform(child);
 	px = parent->ax;
 	py = parent->ay;
 	psx = parent->ascaleX;
diff --git a/spine-c/spine-c/src/spine/PathConstraint.c b/spine-c/spine-c/src/spine/PathConstraint.c
index e6c6ff043..de118b302 100644
--- a/spine-c/spine-c/src/spine/PathConstraint.c
+++ b/spine-c/spine-c/src/spine/PathConstraint.c
@@ -221,7 +221,7 @@ void spPathConstraint_update(spPathConstraint *self) {
 			CONST_CAST(float, bone->c) = sine * a + cosine * c;
 			CONST_CAST(float, bone->d) = sine * b + cosine * d;
 		}
-		CONST_CAST(int, bone->appliedValid) = -1;
+		spBone_updateAppliedTransform(bone);
 	}
 }
 
diff --git a/spine-c/spine-c/src/spine/Skeleton.c b/spine-c/spine-c/src/spine/Skeleton.c
index 4a6c6a961..c694e9391 100644
--- a/spine-c/spine-c/src/spine/Skeleton.c
+++ b/spine-c/spine-c/src/spine/Skeleton.c
@@ -398,13 +398,25 @@ void spSkeleton_updateCache(spSkeleton *self) {
 }
 
 void spSkeleton_updateWorldTransform(const spSkeleton *self) {
-	int i;
+	int i, n;
 	_spSkeleton *internal = SUB_CAST(_spSkeleton, self);
+
+	for (i = 0, n = self->bonesCount; i < n; i++) {
+		spBone *bone = self->bones[i];
+		bone->ax = bone->x;
+		bone->ay = bone->y;
+		bone->arotation = bone->rotation;
+		bone->ascaleX = bone->scaleX;
+		bone->ascaleY = bone->scaleY;
+		bone->ashearX = bone->shearX;
+		bone->ashearY = bone->shearY;
+	}
+	
 	for (i = 0; i < internal->updateCacheCount; ++i) {
 		_spUpdate *update = internal->updateCache + i;
 		switch (update->type) {
 			case SP_UPDATE_BONE:
-				spBone_updateWorldTransform((spBone *) update->object);
+				spBone_update((spBone *) update->object);
 				break;
 			case SP_UPDATE_IK_CONSTRAINT:
 				spIkConstraint_update((spIkConstraint *) update->object);
diff --git a/spine-c/spine-c/src/spine/Slot.c b/spine-c/spine-c/src/spine/Slot.c
index 8ca2ac78f..b3b359f3c 100644
--- a/spine-c/spine-c/src/spine/Slot.c
+++ b/spine-c/spine-c/src/spine/Slot.c
@@ -51,11 +51,31 @@ void spSlot_dispose(spSlot *self) {
 	FREE(self);
 }
 
+static int isVertexAttachment(spAttachment *attachment) {
+	if (attachment == NULL) return 0;
+	switch (attachment->type) {
+		case SP_ATTACHMENT_BOUNDING_BOX:
+		case SP_ATTACHMENT_CLIPPING:
+		case SP_ATTACHMENT_MESH:
+		case SP_ATTACHMENT_PATH:
+			return -1;
+		default:
+			return 0;
+	}
+}
+
 void spSlot_setAttachment(spSlot *self, spAttachment *attachment) {
 	if (attachment == self->attachment) return;
+
+	if (!isVertexAttachment(attachment) ||
+		!isVertexAttachment(self->attachment)
+		|| (SUB_CAST(spVertexAttachment, attachment)->deformAttachment !=
+			SUB_CAST(spVertexAttachment, self->attachment)->deformAttachment)) {
+		self->deformCount = 0;
+	}
+
 	CONST_CAST(spAttachment*, self->attachment) = attachment;
 	SUB_CAST(_spSlot, self)->attachmentTime = self->bone->skeleton->time;
-	self->deformCount = 0;
 }
 
 void spSlot_setAttachmentTime(spSlot *self, float time) {
diff --git a/spine-c/spine-c/src/spine/TransformConstraint.c b/spine-c/spine-c/src/spine/TransformConstraint.c
index 287b5c2f6..1a8dc473d 100644
--- a/spine-c/spine-c/src/spine/TransformConstraint.c
+++ b/spine-c/spine-c/src/spine/TransformConstraint.c
@@ -112,7 +112,7 @@ void _spTransformConstraint_applyAbsoluteWorld(spTransformConstraint *self) {
 			CONST_CAST(float, bone->b) = COS(r) * s;
 			CONST_CAST(float, bone->d) = SIN(r) * s;
 		}
-		CONST_CAST(int, bone->appliedValid) = 0;
+		spBone_updateAppliedTransform(bone);
 	}
 }
 
@@ -172,7 +172,7 @@ void _spTransformConstraint_applyRelativeWorld(spTransformConstraint *self) {
 			CONST_CAST(float, bone->d) = SIN(r) * s;
 		}
 
-		CONST_CAST(int, bone->appliedValid) = 0;
+		spBone_updateAppliedTransform(bone);
 	}
 }
 
@@ -183,10 +183,8 @@ void _spTransformConstraint_applyAbsoluteLocal(spTransformConstraint *self) {
 	int i;
 	float rotation, r, x, y, scaleX, scaleY, shearY;
 
-	if (!target->appliedValid) spBone_updateAppliedTransform(target);
 	for (i = 0; i < self->bonesCount; ++i) {
 		spBone *bone = self->bones[i];
-		if (!bone->appliedValid) spBone_updateAppliedTransform(bone);
 
 		rotation = bone->arotation;
 		if (mixRotate != 0) {
@@ -223,11 +221,8 @@ void _spTransformConstraint_applyRelativeLocal(spTransformConstraint *self) {
 	int i;
 	float rotation, x, y, scaleX, scaleY, shearY;
 
-	if (!target->appliedValid) spBone_updateAppliedTransform(target);
-
 	for (i = 0; i < self->bonesCount; ++i) {
 		spBone *bone = self->bones[i];
-		if (!bone->appliedValid) spBone_updateAppliedTransform(bone);
 
 		rotation = bone->arotation + (target->arotation + self->data->offsetRotation) * mixRotate;
 		x = bone->ax + (target->ax + self->data->offsetX) * mixX;
diff --git a/spine-sfml/c/example/main.cpp b/spine-sfml/c/example/main.cpp
index cbd9d216e..9a054eead 100644
--- a/spine-sfml/c/example/main.cpp
+++ b/spine-sfml/c/example/main.cpp
@@ -225,7 +225,6 @@ void ikDemo (spSkeletonData* skeletonData, spAtlas* atlas) {
         spBone_worldToLocal(crosshair->parent, mouseCoords.x, mouseCoords.y, &boneCoordsX, &boneCoordsY);
         crosshair->x = boneCoordsX;
         crosshair->y = boneCoordsY;
-        crosshair->appliedValid = false;
 
         // Calculate final world transform with the
         // crosshair bone set to the mouse cursor