diff --git a/doc/man1/openssl-ecparam.pod.in b/doc/man1/openssl-ecparam.pod.in
index 4585050514935..d06a97aad6e3a 100644
--- a/doc/man1/openssl-ecparam.pod.in
+++ b/doc/man1/openssl-ecparam.pod.in
@@ -55,14 +55,15 @@ Parameters are encoded as B<EcpkParameters> as specified in IETF RFC 3279.
 
 =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.
+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<-noout>
 
diff --git a/doc/man1/openssl-pkeyparam.pod.in b/doc/man1/openssl-pkeyparam.pod.in
index 5053316c6880a..70d291dbe6467 100644
--- a/doc/man1/openssl-pkeyparam.pod.in
+++ b/doc/man1/openssl-pkeyparam.pod.in
@@ -35,13 +35,15 @@ Print out a usage message.
 
 =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 to write parameters to or standard output if
 this option is not specified.
+The output filename can be the same as the input filename,
+which leads to replacing the file contents in situ.
 
 =item B<-text>