diff --git a/CRM/Dedupe/BAO/DedupeRuleGroup.php b/CRM/Dedupe/BAO/DedupeRuleGroup.php
index 8fa7e35033a2..6faf28ce7988 100644
--- a/CRM/Dedupe/BAO/DedupeRuleGroup.php
+++ b/CRM/Dedupe/BAO/DedupeRuleGroup.php
@@ -59,7 +59,7 @@ public function setContactIds($contactIds) {
    * @return array
    *   a table-keyed array of field-keyed arrays holding supported fields' titles
    */
-  public static function supportedFields($requestedType) {
+  public static function supportedFields($requestedType): array {
     if (!isset(Civi::$statics[__CLASS__]['supportedFields'])) {
       // this is needed, as we're piggy-backing importableFields() below
       $replacements = [
diff --git a/CRM/Dedupe/Finder.php b/CRM/Dedupe/Finder.php
index e4ee36ff30f6..7b276158a40f 100644
--- a/CRM/Dedupe/Finder.php
+++ b/CRM/Dedupe/Finder.php
@@ -262,39 +262,37 @@ public static function formatParams($fields, $ctype) {
     }
 
     $params = [];
-    $supportedFields = CRM_Dedupe_BAO_DedupeRuleGroup::supportedFields($ctype);
-    if (is_array($supportedFields)) {
-      foreach ($supportedFields as $table => $fields) {
-        if ($table === 'civicrm_address') {
-          // for matching on civicrm_address fields, we also need the location_type_id
-          $fields['location_type_id'] = '';
-          // FIXME: we also need to do some hacking for id and name fields, see CRM-3902’s comments
-          $fixes = [
-            'address_name' => 'name',
-            'country' => 'country_id',
-            'state_province' => 'state_province_id',
-            'county' => 'county_id',
-          ];
-          foreach ($fixes as $orig => $target) {
-            if (!empty($flat[$orig])) {
-              $params[$table][$target] = $flat[$orig];
-            }
+
+    foreach (CRM_Dedupe_BAO_DedupeRuleGroup::supportedFields($ctype) as $table => $fields) {
+      if ($table === 'civicrm_address') {
+        // for matching on civicrm_address fields, we also need the location_type_id
+        $fields['location_type_id'] = '';
+        // FIXME: we also need to do some hacking for id and name fields, see CRM-3902’s comments
+        $fixes = [
+          'address_name' => 'name',
+          'country' => 'country_id',
+          'state_province' => 'state_province_id',
+          'county' => 'county_id',
+        ];
+        foreach ($fixes as $orig => $target) {
+          if (!empty($flat[$orig])) {
+            $params[$table][$target] = $flat[$orig];
           }
         }
-        if ($table === 'civicrm_phone') {
-          $fixes = [
-            'phone' => 'phone_numeric',
-          ];
-          foreach ($fixes as $orig => $target) {
-            if (!empty($flat[$orig])) {
-              $params[$table][$target] = $flat[$orig];
-            }
+      }
+      if ($table === 'civicrm_phone') {
+        $fixes = [
+          'phone' => 'phone_numeric',
+        ];
+        foreach ($fixes as $orig => $target) {
+          if (!empty($flat[$orig])) {
+            $params[$table][$target] = $flat[$orig];
           }
         }
-        foreach ($fields as $field => $title) {
-          if (!empty($flat[$field])) {
-            $params[$table][$field] = $flat[$field];
-          }
+      }
+      foreach ($fields as $field => $title) {
+        if (!empty($flat[$field])) {
+          $params[$table][$field] = $flat[$field];
         }
       }
     }