diff --git a/htdocs/blockedlog/ajax/check_signature.php b/htdocs/blockedlog/ajax/check_signature.php
index cc91182293e..ba164e3e715 100644
--- a/htdocs/blockedlog/ajax/check_signature.php
+++ b/htdocs/blockedlog/ajax/check_signature.php
@@ -55,8 +55,10 @@ $blocks = $block_static->getLog('just_certified', 0, 0, 'rowid', 'ASC');
 
 $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 2071eb03c47..4ec3fc6d07e 100644
--- a/htdocs/blockedlog/class/authority.class.php
+++ b/htdocs/blockedlog/class/authority.class.php
@@ -71,8 +71,10 @@ class BlockedLogAuthority
 
 		$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;