diff --git a/include/cpu_des.h b/include/cpu_des.h
index a81209fdd..6ad3c4909 100644
--- a/include/cpu_des.h
+++ b/include/cpu_des.h
@@ -44,7 +44,7 @@
   PERM_OP (l, r, tt,  4, 0x0f0f0f0f);  \
 }
 
-void _des_keysetup (u32 data[2], u32 Kc[16], u32 Kd[16]);
-void _des_encrypt (u32 data[2], u32 Kc[16], u32 Kd[16]);
+void _des_keysetup (const u32 data[2], u32 Kc[16], u32 Kd[16]);
+void _des_encrypt (u32 data[2], const u32 Kc[16], const u32 Kd[16]);
 
 #endif // _CPU_DES_H
diff --git a/include/cpu_md4.h b/include/cpu_md4.h
index f4b667a25..6a61071d0 100644
--- a/include/cpu_md4.h
+++ b/include/cpu_md4.h
@@ -8,6 +8,6 @@
 
 #include <string.h>
 
-void md4_64 (u32 block[16], u32 digest[4]);
+void md4_64 (const u32 block[16], u32 digest[4]);
 
 #endif // _CPU_MD4_H
diff --git a/include/cpu_md5.h b/include/cpu_md5.h
index 33396f926..9fd4f33ac 100644
--- a/include/cpu_md5.h
+++ b/include/cpu_md5.h
@@ -8,7 +8,7 @@
 
 #include <string.h>
 
-void md5_64 (u32 block[16], u32 digest[4]);
+void md5_64 (const u32 block[16], u32 digest[4]);
 void md5_complete_no_limit (u32 digest[4], u32 *plain, u32 plain_len);
 
 #endif // _CPU_MD5_H
diff --git a/include/cpu_sha1.h b/include/cpu_sha1.h
index d8c6dcdcf..138715485 100644
--- a/include/cpu_sha1.h
+++ b/include/cpu_sha1.h
@@ -6,6 +6,6 @@
 #ifndef _CPU_SHA1_H
 #define _CPU_SHA1_H
 
-void sha1_64 (u32 block[16], u32 digest[5]);
+void sha1_64 (const u32 block[16], u32 digest[5]);
 
 #endif // _CPU_SHA1_H
diff --git a/include/cpu_sha256.h b/include/cpu_sha256.h
index 98c9ddc9d..1a48737a1 100644
--- a/include/cpu_sha256.h
+++ b/include/cpu_sha256.h
@@ -6,6 +6,6 @@
 #ifndef _CPU_SHA256_H
 #define _CPU_SHA256_H
 
-void sha256_64 (u32 block[16], u32 digest[8]);
+void sha256_64 (const u32 block[16], u32 digest[8]);
 
 #endif // _CPU_SHA256_H
diff --git a/src/cpu_des.c b/src/cpu_des.c
index 59f349e15..f9b555e73 100644
--- a/src/cpu_des.c
+++ b/src/cpu_des.c
@@ -326,7 +326,7 @@ static const u32 c_skb[8][64] =
   }
 };
 
-void _des_keysetup (u32 data[2], u32 Kc[16], u32 Kd[16])
+void _des_keysetup (const u32 data[2], u32 Kc[16], u32 Kd[16])
 {
   u32 c = data[0];
   u32 d = data[1];
@@ -384,7 +384,7 @@ void _des_keysetup (u32 data[2], u32 Kc[16], u32 Kd[16])
   }
 }
 
-void _des_encrypt (u32 data[2], u32 Kc[16], u32 Kd[16])
+void _des_encrypt (u32 data[2], const u32 Kc[16], const u32 Kd[16])
 {
   u32 r = data[0];
   u32 l = data[1];
diff --git a/src/cpu_md4.c b/src/cpu_md4.c
index 9820ebfe6..77a79ef1a 100644
--- a/src/cpu_md4.c
+++ b/src/cpu_md4.c
@@ -12,7 +12,7 @@
 #include "inc_hash_functions.cl"
 #include "cpu_md4.h"
 
-void md4_64 (u32 block[16], u32 digest[4])
+void md4_64 (const u32 block[16], u32 digest[4])
 {
   u32 w0[4];
   u32 w1[4];
diff --git a/src/cpu_md5.c b/src/cpu_md5.c
index 33797a165..f71c28c72 100644
--- a/src/cpu_md5.c
+++ b/src/cpu_md5.c
@@ -12,7 +12,7 @@
 #include "inc_hash_functions.cl"
 #include "cpu_md5.h"
 
-void md5_64 (u32 block[16], u32 digest[4])
+void md5_64 (const u32 block[16], u32 digest[4])
 {
   u32 w0[4];
   u32 w1[4];
diff --git a/src/cpu_sha1.c b/src/cpu_sha1.c
index 5f7f3612d..3d924983a 100644
--- a/src/cpu_sha1.c
+++ b/src/cpu_sha1.c
@@ -12,7 +12,7 @@
 #include "inc_hash_functions.cl"
 #include "cpu_sha1.h"
 
-void sha1_64 (u32 block[16], u32 digest[5])
+void sha1_64 (const u32 block[16], u32 digest[5])
 {
   u32 a = digest[0];
   u32 b = digest[1];
diff --git a/src/cpu_sha256.c b/src/cpu_sha256.c
index 923523c5f..e9404f9cb 100644
--- a/src/cpu_sha256.c
+++ b/src/cpu_sha256.c
@@ -12,7 +12,7 @@
 #include "inc_hash_functions.cl"
 #include "cpu_sha256.h"
 
-void sha256_64 (u32 block[16], u32 digest[8])
+void sha256_64 (const u32 block[16], u32 digest[8])
 {
   u32 w0_t = block[ 0];
   u32 w1_t = block[ 1];
diff --git a/src/hlfmt.c b/src/hlfmt.c
index d83f85999..6b1cdcca2 100644
--- a/src/hlfmt.c
+++ b/src/hlfmt.c
@@ -86,7 +86,7 @@ static void hlfmt_user_hashcat (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *l
 
 // hlfmt pwdump
 
-static int hlfmt_detect_pwdump (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *line_buf, int line_len)
+static int hlfmt_detect_pwdump (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, const char *line_buf, int line_len)
 {
   int sep_cnt = 0;
 
@@ -183,7 +183,7 @@ static void hlfmt_user_pwdump (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *li
 
 // hlfmt passwd
 
-static int hlfmt_detect_passwd (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *line_buf, int line_len)
+static int hlfmt_detect_passwd (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, const char *line_buf, int line_len)
 {
   int sep_cnt = 0;
 
@@ -266,7 +266,7 @@ static void hlfmt_user_passwd (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *li
 
 // hlfmt shadow
 
-static int hlfmt_detect_shadow (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, char *line_buf, int line_len)
+static int hlfmt_detect_shadow (MAYBE_UNUSED hashcat_ctx_t *hashcat_ctx, const char *line_buf, int line_len)
 {
   int sep_cnt = 0;