diff --git a/doc/man1/openssl-dhparam.pod.in b/doc/man1/openssl-dhparam.pod.in
index f896109164129..20c1f57914261 100644
--- a/doc/man1/openssl-dhparam.pod.in
+++ b/doc/man1/openssl-dhparam.pod.in
@@ -50,14 +50,15 @@ See L<openssl-format-options(1)> for details.
 
 =item B<-in> I<filename>
 
-This specifies the input filename to read parameters from or standard input if
+This specifies the input file to read parameters from or standard input if
 this option is not specified.
 
 =item B<-out> I<filename>
 
-This specifies the output filename parameters to. Standard output is used
-if this option is not present. The output filename should B<not> be the same
-as the input filename.
+This specifies the output file to write parameters to.
+Standard output is used if this option is not present.
+The output filename can be the same as the input filename,
+which leads to replacing the file contents in situ.
 
 =item B<-dsaparam>