diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 64b2910fee..9e0563d7ca 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -5316,11 +5316,11 @@ int PQsetnonblocking(PGconn *conn, int arg);
       </para>
 
       <para>
-       In the nonblocking state, calls to
+       In the nonblocking state, successful calls to
        <xref linkend="libpq-PQsendQuery"/>, <xref linkend="libpq-PQputline"/>,
        <xref linkend="libpq-PQputnbytes"/>, <xref linkend="libpq-PQputCopyData"/>,
-       and <xref linkend="libpq-PQendcopy"/> will not block but instead return
-       an error if they need to be called again.
+       and <xref linkend="libpq-PQendcopy"/> will not block;  their changes
+       are stored in the local output buffer until they are flushed.
       </para>
 
       <para>