--- dissembler.c
+++ dissembler.c
@@ -16,6 +16,9 @@
 
          /*   FOR EDUCATIONAL PURPOSES ONLY  */

+#define _GNU_SOURCE 
+#include <string.h>
+#include <unistd.h>
 #include <stdio.h>
 #include <sys/stat.h>
 #include <ctype.h>
@@ -217,7 +217,7 @@ freedom:
 			fprintf(fh, "P");
 	}
 	fprintf(fh,"\n");
-	if(fh != stdout) close(fh);
+	if(fh != stdout) fclose(fh);
 	free(mem-21);
 }