diff --git a/pkg/atlas/atlas.go b/pkg/atlas/atlas.go
index aaa7fd8..e681ff2 100644
--- a/pkg/atlas/atlas.go
+++ b/pkg/atlas/atlas.go
@@ -11,16 +11,16 @@ type Tile byte
 
 const (
 	// TileNone is a keyword for nothing
-	TileNone = Tile(GlyphNone)
+	TileNone = iota
 
 	// TileRock is solid rock ground
-	TileRock = Tile(GlyphRock)
+	TileRock
 
 	// TileGravel is loose rocks
-	TileGravel = Tile(GlyphGravel)
+	TileGravel
 
 	// TileSand is sand
-	TileSand = Tile(GlyphSand)
+	TileSand
 )
 
 // Glyph returns the glyph for this tile type
diff --git a/pkg/atlas/chunkAtlas.go b/pkg/atlas/chunkAtlas.go
index daee6e6..1d21741 100644
--- a/pkg/atlas/chunkAtlas.go
+++ b/pkg/atlas/chunkAtlas.go
@@ -128,7 +128,7 @@ func (a *chunkBasedAtlas) populate(chunk int) {
 				obj = ObjectSmallRock
 			}
 			if obj != ObjectNone {
-				c.Objects[j*a.ChunkSize+i] = Object{Type: obj}
+				c.Objects[j*a.ChunkSize+i] = Object{Type: ObjectType(obj)}
 			}
 		}
 	}
diff --git a/pkg/atlas/objects.go b/pkg/atlas/objects.go
index 1b9eb87..ac847fe 100644
--- a/pkg/atlas/objects.go
+++ b/pkg/atlas/objects.go
@@ -8,16 +8,16 @@ type ObjectType byte
 // Types of objects
 const (
 	// ObjectNone represents no object at all
-	ObjectNone = ObjectType(GlyphNone)
+	ObjectNone = iota
 
 	// ObjectRover represents a live rover
-	ObjectRover = ObjectType(GlyphRover)
+	ObjectRover
 
 	// ObjectSmallRock is a small stashable rock
-	ObjectSmallRock = ObjectType(GlyphSmallRock)
+	ObjectSmallRock
 
 	// ObjectLargeRock is a large blocking rock
-	ObjectLargeRock = ObjectType(GlyphLargeRock)
+	ObjectLargeRock
 )
 
 // Glyph returns the glyph for this object type