diff --git a/library/error.c b/library/error.c
index 0217767..66e6aa2 100644
--- a/library/error.c
+++ b/library/error.c
@@ -332,7 +332,8 @@
         if( use_ret == -(MBEDTLS_ERR_RSA_RNG_FAILED) )
             mbedtls_snprintf( buf, buflen, "RSA - The random generator failed to generate non-zeros" );
         if( use_ret == -(MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION) )
-            mbedtls_snprintf( buf, buflen, "RSA - The implementation doesn't provide the requested operation" );
+            mbedtls_snprintf( buf, buflen, "RSA - The implementation doesn't offer the requested operation, "\
+                                            "e.g. because of security violations or lack of functionality" );
 #endif /* MBEDTLS_RSA_C */
 
 #if defined(MBEDTLS_SSL_TLS_C)