diff --git a/SMILEBASIC/builtinfunctions.d b/SMILEBASIC/builtinfunctions.d
index ef7ca90..06b694e 100644
--- a/SMILEBASIC/builtinfunctions.d
+++ b/SMILEBASIC/builtinfunctions.d
@@ -1385,27 +1385,26 @@ class BuiltinFunction
     {
         p.sprite.spshow(id);
     }
-    static void SPOFS(PetitComputer p, int id, DefaultValue!double x, DefaultValue!double y, DefaultValue!(int, false) z)
+    static void SPOFS(PetitComputer p, int id, DefaultValue!double x, DefaultValue!double y, DefaultValue!(double, false) z)
     {
         if (x.isDefault || y.isDefault)
         {
-            double x_, y_;
-            int z_;
+            double x_, y_, z_;
             p.sprite.getspofs(id, x_, y_, z_);
             x.setDefaultValue(x_);
             y.setDefaultValue(y_);
         }
         if(z.isDefault)
         {
-            p.sprite.spofs(id, cast(int)x, cast(int)y);
+            p.sprite.spofs(id, cast(double)x, cast(double)y);
         }
         else
         {
-            p.sprite.spofs(id, cast(int)x, cast(int)y, cast(int)z);
+            p.sprite.spofs(id, cast(double)x, cast(double)y, cast(double)z);
         }
     }
     @StartOptional("z")
-    static void SPOFS(PetitComputer p, int id, out double x, out double y, out int z)
+    static void SPOFS(PetitComputer p, int id, out double x, out double y, out double z)
     {
         p.sprite.getspofs(id, x, y, z);
     }
diff --git a/SMILEBASIC/sprite.d b/SMILEBASIC/sprite.d
index 129abba..f85835e 100644
--- a/SMILEBASIC/sprite.d
+++ b/SMILEBASIC/sprite.d
@@ -182,7 +182,7 @@ struct SpriteData
     int defno;
     double x, y;
     int homex, homey;
-    int z;/*!*/
+    double z;/*!*/
     int u, v, w, h;//個々で保持してるみたい,SPSETをして後でSPDEFをしても変化しない
     uint color;
     double[8] var = 0;
@@ -626,7 +626,7 @@ class Sprite
             foreach(i, ref s; sprites)
             {
                 //if(!s.define) continue;
-                auto zet = s.z + 256;
+                auto zet = cast(int)s.z + 256;
                 listptr[i].sprite = &s;
                 if(bucketsptr[zet])
                 {
@@ -895,7 +895,7 @@ class Sprite
             sprites[id].linky = cast(int)(y + (sprites[id].parent ? sprites[id].parent.linky : 0));
         }
     }
-    void spofs(int id, double x, double y, int z)
+    void spofs(int id, double x, double y, double z)
     {
         id = spid(id);
         synchronized (this)
@@ -909,7 +909,7 @@ class Sprite
         }
         zChange = true;
     }
-    void getspofs(int id, out  double x, out double y, out int z)
+    void getspofs(int id, out  double x, out double y, out double z)
     {
         id = spid(id);
         x = sprites[id].x;