diff --git a/missions/techdemo/followtheleader.cpn b/missions/techdemo/followtheleader.cpn
new file mode 100644
index 000000000..589267b38
Binary files /dev/null and b/missions/techdemo/followtheleader.cpn differ
diff --git a/src/cdogs/draw.c b/src/cdogs/draw.c
index 504f212f4..0c31e5115 100644
--- a/src/cdogs/draw.c
+++ b/src/cdogs/draw.c
@@ -239,7 +239,7 @@ void DrawFloor(DrawBuffer *b, int xOffset)
 			 x < b->width;
 			 x++, tile++, pos.x += TILE_WIDTH)
 		{
-			if (PicIsNotNone(tile->pic) &&
+			if (tile->pic != NULL && PicIsNotNone(tile->pic) &&
 				!(tile->flags & (MAPTILE_IS_WALL | MAPTILE_OFFSET_PIC)))
 			{
 				BlitMasked(
diff --git a/src/cdogs/draw_buffer.c b/src/cdogs/draw_buffer.c
index 7ef036356..c395ceebd 100644
--- a/src/cdogs/draw_buffer.c
+++ b/src/cdogs/draw_buffer.c
@@ -102,6 +102,10 @@ void DrawBufferSetFromMap(
 			{
 				*bufTile = map[y][x];
 			}
+			else
+			{
+				*bufTile = tileNone;
+			}
 		}
 		bufTile += tilesXY.x - buffer->width;
 	}
diff --git a/src/cdogs/map.c b/src/cdogs/map.c
index a15f07407..b4ce948b8 100644
--- a/src/cdogs/map.c
+++ b/src/cdogs/map.c
@@ -79,6 +79,7 @@
 #define MAP_ACCESSBITS      0x0F00
 
 
+Tile tileNone = { NULL, { { 0, 0 }, { 0, 0 }, NULL }, 0, 0, NULL };
 Tile gMap[YMAX][XMAX];
 
 
diff --git a/src/cdogs/map.h b/src/cdogs/map.h
index 1dbb9c15b..0fba44705 100644
--- a/src/cdogs/map.h
+++ b/src/cdogs/map.h
@@ -119,6 +119,7 @@ typedef struct
 	TTileItem *things;
 } Tile;
 
+extern Tile tileNone;
 extern Tile gMap[YMAX][XMAX];
 #define Map( x, y)  gMap[y][x]