diff --git a/scripts/sipify.pl b/scripts/sipify.pl
index de74fb35b5a..b9a003216da 100755
--- a/scripts/sipify.pl
+++ b/scripts/sipify.pl
@@ -569,9 +569,11 @@ while ($line_idx < $line_count){
     $line =~ s/SIP_PYNAME\(\s*(\w+)\s*\)/\/PyName=$1\//;
 
     # combine multiple annotations
-    dbg_info("combine multiple annotations -- works only for 2");
     # https://regex101.com/r/uvCt4M/1
-    $line =~ s/\/(\w+(=\w+)?)\/\s*\/(\w+(=\w+)?)\/\s*;(\s*(\/\/.*)?)$/\/$1,$3\/$5;/;
+    do {no warnings 'uninitialized';
+        $line =~ s/\/(\w+(=\w+)?)\/\s*\/(\w+(=\w+)?)\/\s*;(\s*(\/\/.*)?)$/\/$1,$3\/$5;/;
+        ($3 == undef) or dbg_info("combine multiple annotations -- works only for 2");
+    };
 
     # unprinted annotations
     $line =~ s/(\w+)(\<(?>[^<>]|(?2))*\>)?\s+SIP_PYARGTYPE\(\s*\'?([^()']+)(\(\s*(?:[^()]++|(?2))*\s*\))?\'?\s*\)/$3/g;
@@ -657,7 +659,9 @@ while ($line_idx < $line_count){
         next;
     }
     elsif ( $line =~ m/\/\// || $line =~ m/\s*typedef / || $line =~ m/\s*struct / || $line =~ m/operator\[\]\(/ ){
+        dbg_info('skipping comment');
         $comment = '';
+        $return_type = '';
     }
     elsif ( $comment !~ m/^\s*$/ || $return_type ne ''){
         if ( $is_override == 1 && $comment =~ m/^\s*$/ ){
@@ -665,6 +669,7 @@ while ($line_idx < $line_count){
             # parent class Docstring
         }
         else {
+            dbg_info('writing comment');
             push @output, dbg("CM1")."%Docstring\n";
             if ( $comment !~ m/^\s*$/ ){
                 push @output, dbg("CM2")."$comment\n";
diff --git a/tests/scripts/sipifyheader.expected.sip b/tests/scripts/sipifyheader.expected.sip
index 9d73e95811e..eee0e47cd01 100644
--- a/tests/scripts/sipifyheader.expected.sip
+++ b/tests/scripts/sipifyheader.expected.sip
@@ -305,6 +305,11 @@ remove argument
     void position( bool keep, bool keep );
     void position( bool keep );
 
+    Whatever &operator[]( int i ) /Factory/;
+    %MethodCode
+    ....
+    %End
+
     void ZshouldBeShown();
 
     void methodCodeWithMultiLineDef();
diff --git a/tests/scripts/sipifyheader.h b/tests/scripts/sipifyheader.h
index c55b0de3b72..72eb0fe15a3 100644
--- a/tests/scripts/sipifyheader.h
+++ b/tests/scripts/sipifyheader.h
@@ -329,6 +329,14 @@ class CORE_EXPORT QgsSipifyHeader : public QtClass<QVariant>, private Ui::QgsBas
     void position( bool keep, bool middle_remove SIP_PYARGREMOVE, bool keep );
     void position( bool keep, bool last_remove SIP_PYARGREMOVE );
 
+    //! Some comment
+    Whatever &operator[]( int i ) SIP_FACTORY;
+#ifdef SIP_RUN
+    %MethodCode
+    ....
+    %End
+#endif
+
 #if 0
 #if Whatever
     void X();