diff --git a/src/IpRanges.php b/src/IpRanges.php
index fa01d37..5dacf23 100644
--- a/src/IpRanges.php
+++ b/src/IpRanges.php
@@ -6,6 +6,12 @@
 
 use InvalidArgumentException;
 
+use function array_key_exists;
+use function array_merge;
+use function array_unique;
+use function strlen;
+use function strpos;
+
 /**
  * `IpRanges` represents a set of IP ranges that are allowed or forbidden.
  */