diff --git a/app/models/deliverable.rb b/app/models/deliverable.rb
index 70d025b..1d15b64 100644
--- a/app/models/deliverable.rb
+++ b/app/models/deliverable.rb
@@ -17,12 +17,14 @@ class Deliverable < ActiveRecord::Base
   # TODO LATER: Shouldn't require the default_done_ratio patch
   def progress
     return 100 unless self.issues.size > 0
-    
-    total =  self.issues.collect(&:estimated_hours).inject {|sum, n| sum + n}
+
+    total ||=  self.issues.collect(&:estimated_hours).delete_if {|e| e.nil? }.inject {|sum, n| sum + n} || 0
+
+    return 100 unless total > 0
     balance = 0.0
 
     self.issues.each do |issue|
-      balance += issue.status.default_done_ratio * issue.estimated_hours
+      balance += issue.status.default_done_ratio * issue.estimated_hours unless issue.estimated_hours.nil?
     end
 
     return (balance / total).round
diff --git a/spec/models/deliverable_spec.rb b/spec/models/deliverable_spec.rb
index fca962c..2b60581 100644
--- a/spec/models/deliverable_spec.rb
+++ b/spec/models/deliverable_spec.rb
@@ -146,16 +146,16 @@ describe Deliverable, '.progress' do
   it 'should be calculated by the weighted average of the estimated hours of issues' do
     @issue1 = mock_model(Issue)
     @issue1.should_receive(:status).and_return(@status_in_progress)
-    @issue1.should_receive(:estimated_hours).twice.and_return(3.0)
+    @issue1.should_receive(:estimated_hours).exactly(3).times.and_return(3.0)
     @issue2 = mock_model(Issue)
     @issue2.should_receive(:status).and_return(@status_new)
-    @issue2.should_receive(:estimated_hours).twice.and_return(2.0)
+    @issue2.should_receive(:estimated_hours).exactly(3).times.and_return(2.0)
     @issue3 = mock_model(Issue)
     @issue3.should_receive(:status).and_return(@status_pending)
-    @issue3.should_receive(:estimated_hours).twice.and_return(10.0)
+    @issue3.should_receive(:estimated_hours).exactly(3).times.and_return(10.0)
     @issue4 = mock_model(Issue)
     @issue4.should_receive(:status).and_return(@status_complete)
-    @issue4.should_receive(:estimated_hours).twice.and_return(1.0)
+    @issue4.should_receive(:estimated_hours).exactly(3).times.and_return(1.0)
     @issues = [@issue1, @issue2, @issue3, @issue4]
     @issues.stub!(:count).and_return(4)
     
@@ -171,6 +171,36 @@ describe Deliverable, '.progress' do
     
     @deliverable.progress.should eql(100)
   end
+
+  it 'should not count issues with no estimated time' do
+    @issue1 = mock_model(Issue)
+    @issue1.should_receive(:status).and_return(@status_in_progress)
+    @issue1.should_receive(:estimated_hours).exactly(3).times.and_return(3.0)
+    @issue2 = mock_model(Issue)
+    @issue2.should_receive(:estimated_hours).exactly(2).times.and_return(nil)
+    @issues = [@issue1, @issue2]
+    @issues.stub!(:count).and_return(2)
+    
+    @deliverable = Deliverable.new({ :subject => 'test' })
+    @deliverable.should_receive(:issues).exactly(3).times.and_return(@issues)
+    
+    @deliverable.progress.should eql(50)
+  end
+  
+  it 'should return 100 if there are no estimates on any of the assigned issues' do
+    @issue1 = mock_model(Issue)
+    @issue1.should_receive(:estimated_hours).and_return(nil)
+    @issue2 = mock_model(Issue)
+    @issue2.should_receive(:estimated_hours).and_return(nil)
+    @issues = [@issue1, @issue2]
+    @issues.stub!(:count).and_return(2)
+    
+    @deliverable = Deliverable.new({ :subject => 'test' })
+    @deliverable.should_receive(:issues).exactly(2).times.and_return(@issues)
+    
+    @deliverable.progress.should eql(100)
+    
+  end
   
   it 'should not change when hours are clocked'