diff --git a/qrcode/forms/filters.php b/qrcode/forms/filters.php
index 7daba61..eabc649 100644
--- a/qrcode/forms/filters.php
+++ b/qrcode/forms/filters.php
@@ -9,7 +9,7 @@
 						    <!-- SEARCH -->
 							<div class="col-5 col-md-2">
 								<div class="input-group">
-									<input type="text" class="form-control" placeholder="Search" id="input_search" name="search_str" value="<?php echo htmlspecialchars($search_str, ENT_QUOTES, 'UTF-8'); ?>">
+									<input type="text" class="form-control" placeholder="Search" id="input_search" name="search_str" value="<?php echo htmlspecialchars($search_str??'', ENT_QUOTES, 'UTF-8'); ?>">
 									<div class="input-group-append">
 										<span class="input-group-text">
 											<i class="fas fa-search"></i>
@@ -58,4 +58,4 @@ if ($order_dir == 'Desc') {
 		</div><!-- /.row -->
 	</div><!-- /.container-fluid -->
 </div><!-- /.content header -->
-		<hr>
\ No newline at end of file
+		<hr>