diff --git a/app/models/budget/stats.rb b/app/models/budget/stats.rb
index 541c56c3b..7b2e91e74 100644
--- a/app/models/budget/stats.rb
+++ b/app/models/budget/stats.rb
@@ -65,7 +65,7 @@ class Budget::Stats
     end
 
     def balloters
-      budget.ballots.where("ballot_lines_count > ?", 0).pluck(:user_id)
+      budget.ballots.where("ballot_lines_count > ?", 0).pluck(:user_id).compact
     end
 
     def poll_ballot_voters
diff --git a/spec/models/budget/stats_spec.rb b/spec/models/budget/stats_spec.rb
index 99044648c..8eb18ae14 100644
--- a/spec/models/budget/stats_spec.rb
+++ b/spec/models/budget/stats_spec.rb
@@ -69,6 +69,14 @@ describe Budget::Stats do
 
       expect(stats.generate[:total_participants_vote_phase]).to be 1
     end
+
+    it "doesn't count nil user ids" do
+      create(:budget_ballot_line, investment: investment,
+        ballot: create(:budget_ballot, budget: budget, user: nil, physical: true)
+      )
+
+      expect(stats.generate[:total_participants_vote_phase]).to be 0
+    end
   end
 
   describe "#total_participants_web" do