diff --git a/htdocs/blockedlog/ajax/check_signature.php b/htdocs/blockedlog/ajax/check_signature.php
index cc91182293eb3..ba164e3e715b4 100644
--- a/htdocs/blockedlog/ajax/check_signature.php
+++ b/htdocs/blockedlog/ajax/check_signature.php
@@ -55,8 +55,10 @@
 
 $auth->signature = $block_static->getSignature();
 
-foreach ($blocks as &$b) {
-	$auth->blockchain .= $b->signature;
+if (is_array($bocks)) {
+	foreach ($blocks as &$b) {
+		$auth->blockchain .= $b->signature;
+	}
 }
 
 $hash = $auth->getBlockchainHash();
diff --git a/htdocs/blockedlog/class/authority.class.php b/htdocs/blockedlog/class/authority.class.php
index 2071eb03c47ae..4ec3fc6d07ef6 100644
--- a/htdocs/blockedlog/class/authority.class.php
+++ b/htdocs/blockedlog/class/authority.class.php
@@ -71,8 +71,10 @@ public function getLocalBlockChain()
 
 		$this->blockchain = '';
 
-		foreach ($blocks as &$b) {
-			$this->blockchain .= $b->signature;
+		if (is_array($bocks)) {
+			foreach ($blocks as &$b) {
+				$this->blockchain .= $b->signature;
+			}
 		}
 
 		return $this->blockchain;