diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 731e568..104c8f5 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -349,6 +349,10 @@
  *             Note that for both stategies, sizes are measured in blocks and
  *             that an AES block is 16 bytes.
  *
+ * \warning    Upon return, \p stream_block contains sensitive data. Its
+ *             content must not be written to insecure storage and should be
+ *             securely discarded as soon as it's no longer needed.
+ *
  * \param ctx              The AES context to use for encryption or decryption.
  * \param length           The length of the input data.
  * \param nc_off           The offset in the current \p stream_block, for
diff --git a/include/mbedtls/aria.h b/include/mbedtls/aria.h
index 04f9240..bae0621 100644
--- a/include/mbedtls/aria.h
+++ b/include/mbedtls/aria.h
@@ -289,7 +289,7 @@
  *             Note that for both stategies, sizes are measured in blocks and
  *             that an ARIA block is 16 bytes.
  *
- * \warning    Upon return, \p stream_block constains sensitive data. Its
+ * \warning    Upon return, \p stream_block contains sensitive data. Its
  *             content must not be written to insecure storage and should be
  *             securely discarded as soon as it's no longer needed.
  *
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index fb16782..985faa4 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -211,6 +211,10 @@
  *             Note that for both stategies, sizes are measured in blocks and
  *             that a Blowfish block is 8 bytes.
  *
+ * \warning    Upon return, \p stream_block contains sensitive data. Its
+ *             content must not be written to insecure storage and should be
+ *             securely discarded as soon as it's no longer needed.
+ *
  * \param ctx           Blowfish context
  * \param length        The length of the data
  * \param nc_off        The offset in the current stream_block (for resuming
diff --git a/include/mbedtls/camellia.h b/include/mbedtls/camellia.h
index 1d3610f..7e4721a 100644
--- a/include/mbedtls/camellia.h
+++ b/include/mbedtls/camellia.h
@@ -231,6 +231,10 @@
  *             Note that for both stategies, sizes are measured in blocks and
  *             that a CAMELLIA block is 16 bytes.
  *
+ * \warning    Upon return, \p stream_block contains sensitive data. Its
+ *             content must not be written to insecure storage and should be
+ *             securely discarded as soon as it's no longer needed.
+ *
  * \param ctx           CAMELLIA context
  * \param length        The length of the data
  * \param nc_off        The offset in the current stream_block (for resuming