diff --git a/Gemfile.lock b/Gemfile.lock
index 7db2b800d..de94d1788 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -269,8 +269,6 @@ GEM
       activesupport (>= 4.0.1)
       hamlit (>= 1.2.0)
       railties (>= 4.0.1)
-    hamster (3.0.0)
-      concurrent-ruby (~> 1.0)
     hashdiff (1.0.1)
     hashie (4.1.0)
     highline (2.0.3)
@@ -306,14 +304,14 @@ GEM
     iso-639 (0.3.5)
     jmespath (1.5.0)
     json (2.5.1)
-    json-canonicalization (0.2.1)
-    json-ld (3.1.10)
+    json-canonicalization (0.3.0)
+    json-ld (3.2.0)
       htmlentities (~> 4.3)
-      json-canonicalization (~> 0.2)
+      json-canonicalization (~> 0.3)
       link_header (~> 0.0, >= 0.0.8)
-      multi_json (~> 1.14)
-      rack (~> 2.0)
-      rdf (~> 3.1)
+      multi_json (~> 1.15)
+      rack (~> 2.2)
+      rdf (~> 3.2)
     json-ld-preloaded (3.1.6)
       json-ld (~> 3.1)
       rdf (~> 3.1)
@@ -491,8 +489,7 @@ GEM
       thor (~> 1.0)
     rainbow (3.1.1)
     rake (13.0.6)
-    rdf (3.1.15)
-      hamster (~> 3.0)
+    rdf (3.2.3)
       link_header (~> 0.0, >= 0.0.8)
     rdf-normalize (0.4.0)
       rdf (~> 3.1)