diff --git a/Sources/Db/APIs/PostgreSQL.php b/Sources/Db/APIs/PostgreSQL.php
index 5158559e64..e723a0385c 100644
--- a/Sources/Db/APIs/PostgreSQL.php
+++ b/Sources/Db/APIs/PostgreSQL.php
@@ -411,21 +411,13 @@ public function insert(string $method, string $table, array $columns, array $dat
 
 		// PostgreSQL doesn't support replace: we implement a MySQL-compatible behavior instead
 		if ($method == 'replace' || $method == 'ignore') {
-			$key_str = '';
+			$key_str = implode(',', $keys);
 			$col_str = '';
-
 			$count = 0;
-			$count_pk = 0;
 
+			// Make a list of the non-pk fields.
 			foreach ($columns as $columnName => $type) {
-				// Check pk field.
-				if (\in_array($columnName, $keys)) {
-					$key_str .= ($count_pk > 0 ? ',' : '');
-					$key_str .= $columnName;
-					$count_pk++;
-				}
-				// Normal field.
-				elseif ($method == 'replace') {
+				if (!\in_array($columnName, $keys) && ($method == 'replace')) {
 					$col_str .= ($count > 0 ? ',' : '');
 					$col_str .= $columnName . ' = EXCLUDED.' . $columnName;
 					$count++;
diff --git a/Sources/Db/Schema/Table.php b/Sources/Db/Schema/Table.php
index c754e36cac..40f6590938 100644
--- a/Sources/Db/Schema/Table.php
+++ b/Sources/Db/Schema/Table.php
@@ -547,7 +547,7 @@ public function populate(bool $replace = false): int
 			table: '{db_prefix}' . $this->name,
 			columns: Db::$db->getTypeIndicators('{db_prefix}' . $this->name, reset($this->initial_data)),
 			data: array_map(fn($row) => array_values($row), $this->initial_data),
-			keys: isset($auto_col) ? [$auto_col] : [],
+			keys: isset($auto_col) ? [$auto_col] : array_column($this->indexes['primary']->columns, 'name'),
 			returnmode: $returnmode,
 		);