diff --git a/core/src/main/java/org/everit/json/schema/loader/LoadingState.java b/core/src/main/java/org/everit/json/schema/loader/LoadingState.java
index 0503920c2..9b43ad5ac 100644
--- a/core/src/main/java/org/everit/json/schema/loader/LoadingState.java
+++ b/core/src/main/java/org/everit/json/schema/loader/LoadingState.java
@@ -2,7 +2,7 @@
 
 import static java.lang.String.format;
 import static java.util.Objects.requireNonNull;
-import static org.apache.commons.collections.ListUtils.unmodifiableList;
+import static java.util.Collections.unmodifiableList;
 import static org.everit.json.schema.loader.SpecificationVersion.DRAFT_6;
 
 import java.net.URI;
diff --git a/core/src/main/java/org/everit/json/schema/loader/SpecificationVersion.java b/core/src/main/java/org/everit/json/schema/loader/SpecificationVersion.java
index d46608bc3..33e4ea4c5 100644
--- a/core/src/main/java/org/everit/json/schema/loader/SpecificationVersion.java
+++ b/core/src/main/java/org/everit/json/schema/loader/SpecificationVersion.java
@@ -2,8 +2,8 @@
 
 import static java.lang.String.format;
 import static java.util.Arrays.asList;
+import static java.util.Collections.unmodifiableList;
 import static java.util.Collections.unmodifiableMap;
-import static org.apache.commons.collections.ListUtils.unmodifiableList;
 
 import java.util.Arrays;
 import java.util.HashMap;