2 files changed, 2 insertions, 2 deletions
diff --git a/IkiWiki/Plugin/img.pm b/IkiWiki/Plugin/img.pm
index 494fe2335..c3dc41474 100644
--- a/IkiWiki/Plugin/img.pm
+++ b/IkiWiki/Plugin/img.pm
@@ -39,7 +39,7 @@ sub allowed {
 	$allowed = ['jpeg', 'png', 'gif', 'svg'] unless defined $allowed && @$allowed;
 
 	foreach my $a (@$allowed) {
-		return 1 if $a eq $format || $a eq 'everything';
+		return 1 if lc($a) eq $format || lc($a) eq 'everything';
 	}
 
 	return 0;
diff --git a/t/img.t b/t/img.t
index 71b69914e..5531c38d0 100755
--- a/t/img.t
+++ b/t/img.t
@@ -98,7 +98,7 @@ EOF
 );
 ok(utime(333333333, 333333333, "t/tmp/in/imgconversions.mdwn"));
 
-ok(! system(@command, '--set-yaml', 'img_allowed_formats=[jpeg, png, svg, pdf]'));
+ok(! system(@command, '--set-yaml', 'img_allowed_formats=[JPEG, PNG, svg, pdf]'));
 
 sub size($) {
 	my $filename = shift;