diff --git a/plugins/kernel_v2/config/vm.rb b/plugins/kernel_v2/config/vm.rb
index cb3d63e50..8a9de6d38 100644
--- a/plugins/kernel_v2/config/vm.rb
+++ b/plugins/kernel_v2/config/vm.rb
@@ -128,20 +128,27 @@ module VagrantPlugins
 
           # Merge defined disks
           other_disks = other.instance_variable_get(:@disks)
-          new_disks   = @disks.dup
-          @disks.each do |d|
-            other_d = other_disks.find { |o| d.id == o.id }
-            if other_d
-              # There is an override. Take it.
-              other_d.config = d.config.merge(other_p.config)
+          new_disks   = []
+          @disks.each do |p|
+            other_p = other_disks.find { |o| p.id == o.id }
+            if other_p
+              # there is an override. take it.
+              other_p.config = p.config.merge(other_p.config)
+              #other_p.run    ||= p.run
+              #next if !other_p.preserve_order
+
+              # we're preserving order, delete from other
+              p = other_p
+              other_disks.delete(other_p)
             end
 
-            # There is an override, merge it into the
-            new_disks << d.dup
+            # there is an override, merge it into the
+            new_disks << p.dup
           end
-          other_disks.each do |d|
-            new_disks << d.dup
+          other_disks.each do |p|
+            new_disks << p.dup
           end
+          result.instance_variable_set(:@disks, new_disks)
 
           # Merge the providers by prepending any configuration blocks we
           # have for providers onto the new configuration.
@@ -173,17 +180,17 @@ module VagrantPlugins
           @provisioners.each do |p|
             other_p = other_provs.find { |o| p.id == o.id }
             if other_p
-              # There is an override. Take it.
+              # there is an override. take it.
               other_p.config = p.config.merge(other_p.config)
               other_p.run    ||= p.run
               next if !other_p.preserve_order
 
-              # We're preserving order, delete from other
+              # we're preserving order, delete from other
               p = other_p
               other_provs.delete(other_p)
             end
 
-            # There is an override, merge it into the
+            # there is an override, merge it into the
             new_provs << p.dup
           end
           other_provs.each do |p|
diff --git a/test/unit/plugins/kernel_v2/config/vm_test.rb b/test/unit/plugins/kernel_v2/config/vm_test.rb
index 00576cbb3..92f7d7e3c 100644
--- a/test/unit/plugins/kernel_v2/config/vm_test.rb
+++ b/test/unit/plugins/kernel_v2/config/vm_test.rb
@@ -549,6 +549,44 @@ describe VagrantPlugins::Kernel_V2::VMConfig do
     end
   end
 
+  describe "#disk" do
+    it "stores the disks" do
+      subject.disk("disk", size: 100)
+      subject.disk("disk", size: 1000, primary: false, name: "storage")
+      subject.finalize!
+
+      d = subject.disks
+      expect(d.length).to eql(2)
+      expect(d[0].size).to eql(100)
+      expect(d[1].size).to eql(1000)
+      expect(d[1].name).to eql("storage")
+    end
+
+    it "does not merge duplicate disks" do
+      subject.disk("disk", size: 1000, primary: false, name: "storage")
+      subject.disk("disk", size: 1000, primary: false, name: "backup")
+
+      merged = subject.merge(subject)
+      merged_disks = merged.disks
+
+      expect(merged_disks.length).to eql(2)
+    end
+
+    it "ignores non-overriding runs" do
+      subject.disk("disk", name: "foo")
+
+      other = described_class.new
+      other.disk("disk", name: "bar", primary: false)
+
+      merged = subject.merge(other)
+      merged_disks = merged.disks
+
+      expect(merged_disks.length).to eql(2)
+      expect(merged_disks[0].name).to eq("foo")
+      expect(merged_disks[1].name).to eq("bar")
+    end
+  end
+
   describe "#synced_folder(s)" do
     it "defaults to sharing the current directory" do
       subject.finalize!