diff --git a/include/mbedtls/rsa.h b/include/mbedtls/rsa.h
index 046bfc5..90a5907 100644
--- a/include/mbedtls/rsa.h
+++ b/include/mbedtls/rsa.h
@@ -738,7 +738,7 @@
 
 /**
  * \brief          Encode a hash into a DigestInfo structure as specified
- *                 by PKCS#1(RFC 8017, EMSA-PKCS1-v1_5-ENCODE step 2).
+ *                 by PKCS#1 (RFC 8017, EMSA-PKCS1-v1_5-ENCODE step 2).
  *                 Note: function works backwards in data buffer.
  *
  * \param p        Reference to the current position pointer