Index: src/book.c
===================================================================
--- src/book.c.orig
+++ src/book.c
@@ -343,9 +343,11 @@ int BookBuilderOpen(void)
     }
     digest_bits = MAX_DIGEST_BITS;
     /* We use read_book() here only to allocate memory */
-    if (read_book(wfp) == BOOK_ENOMEM) {
+    if (read_book(rfp) == BOOK_ENOMEM) {
+      fclose(rfp);
       return BOOK_ENOMEM;
     }
+    fclose(rfp);
   }
   return BOOK_SUCCESS;
 }