diff --git a/bin/pt-agent b/bin/pt-agent
index c80318c6..d6cbe1e9 100755
--- a/bin/pt-agent
+++ b/bin/pt-agent
@@ -3612,12 +3612,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-align b/bin/pt-align
index ad87df2b..5808d428 100755
--- a/bin/pt-align
+++ b/bin/pt-align
@@ -1077,12 +1077,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-archiver b/bin/pt-archiver
index 6fb28d95..3f78a1a8 100755
--- a/bin/pt-archiver
+++ b/bin/pt-archiver
@@ -1804,12 +1804,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-config-diff b/bin/pt-config-diff
index d97901b9..356a860b 100755
--- a/bin/pt-config-diff
+++ b/bin/pt-config-diff
@@ -1804,12 +1804,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-deadlock-logger b/bin/pt-deadlock-logger
index 8e454287..8aee04c5 100755
--- a/bin/pt-deadlock-logger
+++ b/bin/pt-deadlock-logger
@@ -1154,12 +1154,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-diskstats b/bin/pt-diskstats
index c9818ef3..8e3c1ba2 100755
--- a/bin/pt-diskstats
+++ b/bin/pt-diskstats
@@ -1150,12 +1150,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-duplicate-key-checker b/bin/pt-duplicate-key-checker
index f4e9c7d4..248cdd54 100755
--- a/bin/pt-duplicate-key-checker
+++ b/bin/pt-duplicate-key-checker
@@ -2136,12 +2136,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-fifo-split b/bin/pt-fifo-split
index b6075dda..d7dd2d25 100755
--- a/bin/pt-fifo-split
+++ b/bin/pt-fifo-split
@@ -1078,12 +1078,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-find b/bin/pt-find
index 87b60138..9cd59bfc 100755
--- a/bin/pt-find
+++ b/bin/pt-find
@@ -1570,12 +1570,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-fingerprint b/bin/pt-fingerprint
index 7c6eb086..d7224f23 100755
--- a/bin/pt-fingerprint
+++ b/bin/pt-fingerprint
@@ -1079,12 +1079,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-fk-error-logger b/bin/pt-fk-error-logger
index 648675a6..1800847e 100755
--- a/bin/pt-fk-error-logger
+++ b/bin/pt-fk-error-logger
@@ -1149,12 +1149,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-heartbeat b/bin/pt-heartbeat
index 7539a87e..eed1c14e 100755
--- a/bin/pt-heartbeat
+++ b/bin/pt-heartbeat
@@ -1886,12 +1886,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-index-usage b/bin/pt-index-usage
index 7c9ae8cf..c0211ea9 100755
--- a/bin/pt-index-usage
+++ b/bin/pt-index-usage
@@ -1731,12 +1731,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-kill b/bin/pt-kill
index 4d4ba507..d4cefe4f 100755
--- a/bin/pt-kill
+++ b/bin/pt-kill
@@ -1159,12 +1159,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-online-schema-change b/bin/pt-online-schema-change
index d0e1a5da..51b6177b 100755
--- a/bin/pt-online-schema-change
+++ b/bin/pt-online-schema-change
@@ -1166,12 +1166,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-query-digest b/bin/pt-query-digest
index 5b9a5a53..c1b27afb 100755
--- a/bin/pt-query-digest
+++ b/bin/pt-query-digest
@@ -2399,12 +2399,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-show-grants b/bin/pt-show-grants
index 13fc8517..9bd0f422 100755
--- a/bin/pt-show-grants
+++ b/bin/pt-show-grants
@@ -1079,12 +1079,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-slave-delay b/bin/pt-slave-delay
index 2c85dea8..f6eef96e 100755
--- a/bin/pt-slave-delay
+++ b/bin/pt-slave-delay
@@ -1152,12 +1152,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-slave-find b/bin/pt-slave-find
index 191ccbc9..b5cf1f1f 100755
--- a/bin/pt-slave-find
+++ b/bin/pt-slave-find
@@ -1087,12 +1087,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-slave-restart b/bin/pt-slave-restart
index f5e32ec4..508661b9 100755
--- a/bin/pt-slave-restart
+++ b/bin/pt-slave-restart
@@ -1304,12 +1304,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-table-checksum b/bin/pt-table-checksum
index e97f260d..b89e8e01 100755
--- a/bin/pt-table-checksum
+++ b/bin/pt-table-checksum
@@ -2833,12 +2833,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-table-sync b/bin/pt-table-sync
index b388a41a..2b79084c 100755
--- a/bin/pt-table-sync
+++ b/bin/pt-table-sync
@@ -1167,12 +1167,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-table-usage b/bin/pt-table-usage
index e900d1cd..f12be779 100755
--- a/bin/pt-table-usage
+++ b/bin/pt-table-usage
@@ -1516,12 +1516,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-upgrade b/bin/pt-upgrade
index 628e92c9..644a291c 100755
--- a/bin/pt-upgrade
+++ b/bin/pt-upgrade
@@ -2396,12 +2396,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-variable-advisor b/bin/pt-variable-advisor
index a64031f3..75fd03af 100755
--- a/bin/pt-variable-advisor
+++ b/bin/pt-variable-advisor
@@ -1156,12 +1156,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }
 
diff --git a/bin/pt-visual-explain b/bin/pt-visual-explain
index d9b57c99..b41da53e 100755
--- a/bin/pt-visual-explain
+++ b/bin/pt-visual-explain
@@ -1753,12 +1753,12 @@ sub _d {
 }
 
 if ( PTDEBUG ) {
-   print '# ', $^X, ' ', $], "\n";
+   print STDERR '# ', $^X, ' ', $], "\n";
    if ( my $uname = `uname -a` ) {
       $uname =~ s/\s+/ /g;
-      print "# $uname\n";
+      print STDERR "# $uname\n";
    }
-   print '# Arguments: ',
+   print STDERR '# Arguments: ',
       join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
 }