diff --git a/gen.c b/gen.c
index 13842ac..b00d13f 100644
--- a/gen.c
+++ b/gen.c
@@ -86,6 +86,9 @@ Chunk fetch_chunk(int x, int y, int z, int ci) {
     fclose(fp);
     return chunk;
   }
+  if (fp != 0) {
+    fclose(fp);
+  }
   if (!fp) {
     fp = fopen(fname, "wb");
   }