diff --git a/tools/env/fw_env.h b/tools/env/fw_env.h
index 57149e7..7345922 100644
--- a/tools/env/fw_env.h
+++ b/tools/env/fw_env.h
@@ -78,12 +78,12 @@
 
 int parse_aes_key(char *key, uint8_t *bin_key);
 
-extern int   fw_printenv(int argc, char *argv[]);
-extern char *fw_getenv  (char *name);
-extern int fw_setenv  (int argc, char *argv[]);
-extern int fw_parse_script(char *fname);
-extern int fw_env_open(void);
-extern int fw_env_write(char *name, char *value);
-extern int fw_env_close(void);
+int   fw_printenv(int argc, char *argv[]);
+char *fw_getenv(char *name);
+int fw_setenv(int argc, char *argv[]);
+int fw_parse_script(char *fname);
+int fw_env_open(void);
+int fw_env_write(char *name, char *value);
+int fw_env_close(void);
 
-extern unsigned	long  crc32	 (unsigned long, const unsigned char *, unsigned);
+unsigned long crc32(unsigned long, const unsigned char *, unsigned);