diff --git a/cmd/crc.c b/cmd/crc.c
index 4aedef5..b872e6c 100644
--- a/cmd/crc.c
+++ b/cmd/crc.c
@@ -1,3 +1,5 @@
+#pragma GCC optimize("Ofast")
+
 #include <endian.h>
 #include <stdio.h>
 #include <unistd.h>
diff --git a/include/crc.h b/include/crc.h
index d33f013..bf3b74a 100644
--- a/include/crc.h
+++ b/include/crc.h
@@ -1,3 +1,4 @@
+#pragma once
 
 int check_file_header(char *addr);
 int check_header_length(unsigned char *addr, long offset);
diff --git a/include/crc_util.h b/include/crc_util.h
index be0a513..5670cdb 100644
--- a/include/crc_util.h
+++ b/include/crc_util.h
@@ -1,6 +1,8 @@
 #include <stdio.h>
 #include <stdint.h>
 
+#pragma once
+
 // PNG File Struct
 struct PNG_START_FILE_STRUCT {
 	unsigned char file_sig[8];