Index: latex2html-2017.2/styles/frames.perl
===================================================================
--- latex2html-2017.2.orig/styles/frames.perl
+++ latex2html-2017.2/styles/frames.perl
@@ -295,7 +295,7 @@ sub check_frame_colorset {
     elsif ($reverse == 1) {$colorset="${which}_colorset_star"}
     elsif ($reverse == 2) {$colorset="${which}_colorset_star_star"}
     else {$colorset="${which}_colorset"}
-    if (!(defined  @$colorset))
+    if (!(@$colorset))
 	{ print STDERR "\nframes for $which are not supported\n"; return($rest);}	
     local($frame_tmp)=$frame_data;
     local($key, @values);
Index: latex2html-2017.2/styles/natbib.perl
===================================================================
--- latex2html-2017.2.orig/styles/natbib.perl
+++ latex2html-2017.2/styles/natbib.perl
@@ -1451,7 +1451,7 @@ sub do_cmd_citestyle {
     local($_) = @_;
     s/$next_pair_pr_rx//o;
     local($style)="citestyle_$2";
-    if (defined @$style) {
+    if (@$style) {
 	($CITE_OPEN_DELIM,
 	 $CITE_CLOSE_DELIM,
 	 $CITE_ENUM,