diff --git a/include/polarssl/rsa.h b/include/polarssl/rsa.h
index b1354d196..e80bb4da0 100644
--- a/include/polarssl/rsa.h
+++ b/include/polarssl/rsa.h
@@ -199,6 +199,7 @@ int rsa_check_pub_priv( const rsa_context *pub, const rsa_context *prv );
 
 /**
  * \brief          Do an RSA public key operation
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param input    input buffer
@@ -219,6 +220,7 @@ int rsa_public( rsa_context *ctx,
 
 /**
  * \brief          Do an RSA private key operation
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for blinding)
@@ -241,6 +243,7 @@ int rsa_private( rsa_context *ctx,
  * \brief          Generic wrapper to perform a PKCS#1 encryption using the
  *                 mode from the context. Add the message padding, then do an
  *                 RSA operation.
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for padding and PKCS#1 v2.1 encoding
@@ -265,6 +268,7 @@ int rsa_pkcs1_encrypt( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v1.5 encryption (RSAES-PKCS1-v1_5-ENCRYPT)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for padding and RSA_PRIVATE)
@@ -288,6 +292,7 @@ int rsa_rsaes_pkcs1_v15_encrypt( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v2.1 OAEP encryption (RSAES-OAEP-ENCRYPT)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for padding and PKCS#1 v2.1 encoding
@@ -318,6 +323,7 @@ int rsa_rsaes_oaep_encrypt( rsa_context *ctx,
  * \brief          Generic wrapper to perform a PKCS#1 decryption using the
  *                 mode from the context. Do an RSA operation, then remove
  *                 the message padding
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -344,6 +350,7 @@ int rsa_pkcs1_decrypt( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v1.5 decryption (RSAES-PKCS1-v1_5-DECRYPT)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -370,6 +377,7 @@ int rsa_rsaes_pkcs1_v15_decrypt( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v2.1 OAEP decryption (RSAES-OAEP-DECRYPT)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -402,6 +410,7 @@ int rsa_rsaes_oaep_decrypt( rsa_context *ctx,
  * \brief          Generic wrapper to perform a PKCS#1 signature using the
  *                 mode from the context. Do a private RSA operation to sign
  *                 a message digest
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for PKCS#1 v2.1 encoding and for
@@ -460,6 +469,7 @@ int rsa_rsassa_pkcs1_v15_sign( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v2.1 PSS signature (RSASSA-PSS-SIGN)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      RSA context
  * \param f_rng    RNG function (Needed for PKCS#1 v2.1 encoding and for
@@ -495,6 +505,7 @@ int rsa_rsassa_pss_sign( rsa_context *ctx,
  * \brief          Generic wrapper to perform a PKCS#1 verification using the
  *                 mode from the context. Do a public RSA operation and check
  *                 the message digest
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      points to an RSA public key
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -525,6 +536,7 @@ int rsa_pkcs1_verify( rsa_context *ctx,
 
 /**
  * \brief          Perform a PKCS#1 v1.5 verification (RSASSA-PKCS1-v1_5-VERIFY)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      points to an RSA public key
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -553,6 +565,7 @@ int rsa_rsassa_pkcs1_v15_verify( rsa_context *ctx,
 /**
  * \brief          Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY)
  *                 (This is the "simple" version.)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      points to an RSA public key
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)
@@ -587,6 +600,7 @@ int rsa_rsassa_pss_verify( rsa_context *ctx,
 /**
  * \brief          Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY)
  *                 (This is the version with "full" options.)
+ *                 (Thread-safe if POLARSSL_THREADING_C is enabled)
  *
  * \param ctx      points to an RSA public key
  * \param f_rng    RNG function (Only needed for RSA_PRIVATE)