diff --git a/src/powder.c b/src/powder.c
index aabea3436..827995c8f 100644
--- a/src/powder.c
+++ b/src/powder.c
@@ -705,7 +705,7 @@ inline int create_part(int p, int x, int y, int tv)//the function for creating a
 	int t = tv & 0xFF;
 	int v = (tv >> 8) & 0xFF;
 	
-	if (x<0 || y<0 || x>=XRES || y>=YRES || ((t<0 || t>=PT_NUM)&&t!=SPC_HEAT&&t!=SPC_COOL&&t!=SPC_AIR&&t!=SPC_VACUUM&&t!=SPC_PGRV&&t!=SPC_NGRV))
+	if (x<0 || y<0 || x>=XRES || y>=YRES || ((t<=0 || t>=PT_NUM)&&t!=SPC_HEAT&&t!=SPC_COOL&&t!=SPC_AIR&&t!=SPC_VACUUM&&t!=SPC_PGRV&&t!=SPC_NGRV))
 		return -1;
 	if (t>=0 && t<PT_NUM && !ptypes[t].enabled)
 		return -1;