diff --git a/include/polarssl/pkcs11.h b/include/polarssl/pkcs11.h
index efe7f14be..5087e1951 100644
--- a/include/polarssl/pkcs11.h
+++ b/include/polarssl/pkcs11.h
@@ -97,7 +97,7 @@ int pkcs11_decrypt( pkcs11_context *ctx,
                        int mode, int *olen,
                        const unsigned char *input,
                        unsigned char *output,
-                       int output_max_len );
+                       unsigned int output_max_len );
 
 /**
  * \brief          Do a private RSA to sign a message digest
diff --git a/library/cipher.c b/library/cipher.c
index 545b2dac0..345e2fee1 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -366,6 +366,8 @@ int cipher_finish( cipher_context_t *ctx, unsigned char *output, int *olen)
 
 int cipher_self_test( int verbose )
 {
+    ((void) verbose);
+
     return( 0 );
 }
 
diff --git a/library/cipher_wrap.c b/library/cipher_wrap.c
index b5cce5a90..dd41a353b 100644
--- a/library/cipher_wrap.c
+++ b/library/cipher_wrap.c
@@ -203,31 +203,43 @@ int des3_crypt_cbc_wrap( void *ctx, operation_t operation, int length,
 
 int des_setkey_dec_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des_setkey_dec( (des_context *) ctx, key );
 }
 
 int des_setkey_enc_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des_setkey_enc( (des_context *) ctx, key );
 }
 
 int des3_set2key_dec_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des3_set2key_dec( (des3_context *) ctx, key );
 }
 
 int des3_set2key_enc_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des3_set2key_enc( (des3_context *) ctx, key );
 }
 
 int des3_set3key_dec_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des3_set3key_dec( (des3_context *) ctx, key );
 }
 
 int des3_set3key_enc_wrap( void *ctx, const unsigned char *key, int key_length )
 {
+    ((void) key_length);
+
     return des3_set3key_enc( (des3_context *) ctx, key );
 }
 
diff --git a/library/pkcs11.c b/library/pkcs11.c
index 172ffc1f6..b4f478763 100644
--- a/library/pkcs11.c
+++ b/library/pkcs11.c
@@ -116,7 +116,7 @@ int pkcs11_decrypt( pkcs11_context *ctx,
                        int mode, int *olen,
                        const unsigned char *input,
                        unsigned char *output,
-                       int output_max_len )
+                       unsigned int output_max_len )
 {
     size_t input_len, output_len;
 
diff --git a/library/x509parse.c b/library/x509parse.c
index 378f0a956..0e410f4ac 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -776,7 +776,7 @@ static int x509_get_ns_cert_type( unsigned char **p,
                                        unsigned char *ns_cert_type)
 {
     int ret;
-    x509_bitstring bs = {0};
+    x509_bitstring bs = { 0, 0, NULL };
 
     if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
         return( POLARSSL_ERR_X509_CERT_INVALID_EXTENSIONS | ret );
@@ -795,7 +795,7 @@ static int x509_get_key_usage( unsigned char **p,
                                unsigned char *key_usage)
 {
     int ret;
-    x509_bitstring bs = {0};
+    x509_bitstring bs = { 0, 0, NULL };
 
     if( ( ret = asn1_get_bitstring( p, end, &bs ) ) != 0 )
         return( POLARSSL_ERR_X509_CERT_INVALID_EXTENSIONS | ret );