diff --git a/lib/bundler/dep_proxy.rb b/lib/bundler/dep_proxy.rb
index 7a9423b14aa..6c32179ac18 100644
--- a/lib/bundler/dep_proxy.rb
+++ b/lib/bundler/dep_proxy.rb
@@ -10,11 +10,11 @@ def initialize(dep, platform)
     end
 
     def hash
-      @hash ||= dep.hash
+      @hash ||= [dep, __platform].hash
     end
 
     def ==(other)
-      return if other.nil?
+      return false if other.class != self.class
       dep == other.dep && __platform == other.__platform
     end
 
diff --git a/spec/bundler/dep_proxy_spec.rb b/spec/bundler/dep_proxy_spec.rb
new file mode 100644
index 00000000000..0f8d6b1076a
--- /dev/null
+++ b/spec/bundler/dep_proxy_spec.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+RSpec.describe Bundler::DepProxy do
+  let(:dep) { Bundler::Dependency.new("rake", ">= 0") }
+  subject { described_class.new(dep, Gem::Platform::RUBY) }
+  let(:same) { subject }
+  let(:other) { subject.dup }
+  let(:different) { described_class.new(dep, Gem::Platform::JAVA) }
+
+  describe "#eql?" do
+    it { expect(subject.eql?(same)).to be true }
+    it { expect(subject.eql?(other)).to be true }
+    it { expect(subject.eql?(different)).to be false }
+    it { expect(subject.eql?(nil)).to be false }
+    it { expect(subject.eql?("foobar")).to be false }
+  end
+
+  describe "#hash" do
+    it { expect(subject.hash).to eq(same.hash) }
+    it { expect(subject.hash).to eq(other.hash) }
+  end
+end