diff --git a/lib/rubygems/resolver/molinillo.rb b/lib/rubygems/resolver/molinillo.rb
index d703505410..03b613b789 100644
--- a/lib/rubygems/resolver/molinillo.rb
+++ b/lib/rubygems/resolver/molinillo.rb
@@ -1,3 +1,3 @@
 # frozen_string_literal: true
 
-require_relative "molinillo/lib/molinillo"
+require_relative "../vendor/molinillo/lib/molinillo"
diff --git a/lib/rubygems/resolver/molinillo/.document b/lib/rubygems/vendor/molinillo/.document
similarity index 100%
rename from lib/rubygems/resolver/molinillo/.document
rename to lib/rubygems/vendor/molinillo/.document
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo.rb b/lib/rubygems/vendor/molinillo/lib/molinillo.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/delegates/resolution_state.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/delegates/resolution_state.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/delegates/resolution_state.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/delegates/resolution_state.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/delegates/specification_provider.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/delegates/specification_provider.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/delegates/specification_provider.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/delegates/specification_provider.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/action.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/action.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/action.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/action.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/add_vertex.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_vertex.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/add_vertex.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_vertex.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/delete_edge.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/delete_edge.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/delete_edge.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/delete_edge.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/detach_vertex_named.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/detach_vertex_named.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/detach_vertex_named.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/detach_vertex_named.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/log.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/log.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/log.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/log.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/set_payload.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/set_payload.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/set_payload.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/set_payload.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/tag.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/tag.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/tag.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/tag.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/vertex.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/vertex.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/dependency_graph/vertex.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/vertex.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/errors.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/errors.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/errors.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/errors.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/gem_metadata.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/gem_metadata.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/gem_metadata.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/gem_metadata.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/modules/specification_provider.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/modules/specification_provider.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/modules/specification_provider.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/modules/specification_provider.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/modules/ui.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/modules/ui.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/modules/ui.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/modules/ui.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/resolution.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/resolution.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/resolution.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/resolution.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/resolver.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/resolver.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/resolver.rb
diff --git a/lib/rubygems/resolver/molinillo/lib/molinillo/state.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/state.rb
similarity index 100%
rename from lib/rubygems/resolver/molinillo/lib/molinillo/state.rb
rename to lib/rubygems/vendor/molinillo/lib/molinillo/state.rb