diff --git a/core/lib/Foswiki/PageCache.pm b/core/lib/Foswiki/PageCache.pm
index c95a3644e3..5266e6e198 100644
--- a/core/lib/Foswiki/PageCache.pm
+++ b/core/lib/Foswiki/PageCache.pm
@@ -683,6 +683,14 @@ sub _handleDirtyArea {
         $prefs->popTopicContext();
     };
 
+    my $request = $session->{request};
+    my $context = $request->url( -full => 1, -path => 1, -query => 1 ) . time();
+    my $cgis    = $session->{users}->getCGISession();
+    my $usingStrikeOne = $Foswiki::cfg{Validation}{Method} eq 'strikeone';
+
+    $text =~
+s/<input type='hidden' name='validation_key' value='(\?.*?)' \/>/Foswiki::Validation::updateValidationKey($cgis, $context, $usingStrikeOne, $1)/gei;
+
     #Foswiki::Func::writeDebug("out text='$text'") if TRACE;
     return $text;
 }
diff --git a/core/lib/Foswiki/Validation.pm b/core/lib/Foswiki/Validation.pm
index 5441c3278d..c4ae7c4591 100644
--- a/core/lib/Foswiki/Validation.pm
+++ b/core/lib/Foswiki/Validation.pm
@@ -92,6 +92,15 @@ sub addValidationKey {
     return "<input type='hidden' name='validation_key' value='?$nonce' />";
 }
 
+sub updateValidationKey {
+    my ( $cgis, $context, $strikeone, $oldKey ) = @_;
+
+    # expire old key
+    expireValidationKeys( $cgis, $oldKey );
+
+    return addValidationKey( $cgis, $context, $strikeone );
+}
+
 =begin TML
 
 ---++ StaticMethod generateValidationKey( $cgis, $context, $strikeone ) -> $nonce