diff --git a/autotests/folding/highlight.pl.fold b/autotests/folding/highlight.pl.fold
--- a/autotests/folding/highlight.pl.fold
+++ b/autotests/folding/highlight.pl.fold
@@ -73,3 +73,7 @@
         ...
     <endfold id='4'>}</endfold id='4'>
 <endfold id='4'>}</endfold id='4'>
+
+# Highlight correctly operator // (bug #407327)
+$x = ns // <beginfold id='2'>"</beginfold id='2'><endfold id='2'>"</endfold id='2'>;
+print $x;
diff --git a/autotests/html/highlight.pl.html b/autotests/html/highlight.pl.html
--- a/autotests/html/highlight.pl.html
+++ b/autotests/html/highlight.pl.html
@@ -79,4 +79,8 @@
         ...
     }
 }
+
+<span style="color:#898887;"># Highlight correctly operator // (bug #407327)</span>
+<span style="color:#0057ae;">$x</span> = ns // <span style="color:#008000;font-weight:bold;">&quot;&quot;</span>;
+<span style="color:#644a9b;">print</span> <span style="color:#0057ae;">$x</span>;
 </pre></body></html>
diff --git a/autotests/input/highlight.pl b/autotests/input/highlight.pl
--- a/autotests/input/highlight.pl
+++ b/autotests/input/highlight.pl
@@ -73,3 +73,7 @@
         ...
     }
 }
+
+# Highlight correctly operator // (bug #407327)
+$x = ns // "";
+print $x;
diff --git a/autotests/reference/highlight.pl.ref b/autotests/reference/highlight.pl.ref
--- a/autotests/reference/highlight.pl.ref
+++ b/autotests/reference/highlight.pl.ref
@@ -73,3 +73,7 @@
 <Normal Text>        ...</Normal Text><br/>
 <Normal Text>    }</Normal Text><br/>
 <Normal Text>}</Normal Text><br/>
+<Normal Text></Normal Text><br/>
+<Comment># Highlight correctly operator // (bug #407327)</Comment><br/>
+<Data Type>$x</Data Type><Normal Text> = ns // </Normal Text><Operator>""</Operator><Normal Text>;</Normal Text><br/>
+<Function>print</Function><Normal Text> </Normal Text><Data Type>$x</Data Type><Normal Text>;</Normal Text><br/>
diff --git a/data/syntax/perl.xml b/data/syntax/perl.xml
--- a/data/syntax/perl.xml
+++ b/data/syntax/perl.xml
@@ -39,7 +39,7 @@
 
    Enhance tr/// and y/// support.
 -->
-<language name="Perl" version="7" kateversion="2.4" section="Scripts" extensions="*.pl;*.PL;*.pm;*.pl6;*.PL6;*.p6;*.pm6;" mimetype="application/x-perl;text/x-perl" priority="5" author="Anders Lund (anders@alweb.dk)" license="LGPLv2">
+<language name="Perl" version="8" kateversion="2.4" section="Scripts" extensions="*.pl;*.PL;*.pm;*.pl6;*.PL6;*.p6;*.pm6;" mimetype="application/x-perl;text/x-perl" priority="5" author="Anders Lund (anders@alweb.dk)" license="LGPLv2">
   <highlighting>
     <list name="keywords">
       <item>if</item>
@@ -383,8 +383,11 @@
 
         <RegExpr attribute="Operator" context="find_pattern" String="\b(?:m|qr)(?=\s*[^\w\s\]})])" />
 
-        <RegExpr attribute="Normal Text" context="#stay" String="[\w_]+\s*/" />
-        <RegExpr attribute="Normal Text" context="#stay" String="[&lt;&gt;&quot;':]/" />
+        <RegExpr attribute="Normal Text" context="#stay" String="[\w_]+\s*//?\=?" />
+        <RegExpr attribute="Normal Text" context="#stay" String="[&lt;&gt;&quot;':]//?\=?" />
+        <!-- Avoid conflicts between operators / and // -->
+        <StringDetect attribute="Normal Text" context="#stay" String="//=" />
+        <Detect2Chars attribute="Normal Text" context="#stay" char="/" char1="/" />
         <DetectChar attribute="Operator" context="pattern_slash" char="/" beginRegion="Pattern" />
         <RegExpr attribute="Operator" context="#stay" String="-[rwxoRWXOeszfdlpSbctugkTBMAC]\b" />