diff --git a/app/models/holding.rb b/app/models/holding.rb
index fb9b001e..af659f3e 100644
--- a/app/models/holding.rb
+++ b/app/models/holding.rb
@@ -27,10 +27,18 @@ class Holding < ApplicationRecord
 
   # Basic approximation of cost-basis
   def avg_cost
-    avg_cost = account.entries.trades
-                  .joins("INNER JOIN trades ON trades.id = entries.entryable_id")
-                  .where("trades.security_id = ? AND trades.qty > 0 AND entries.date <= ?", security.id, date)
-                  .average(:price)
+    avg_cost = account.trades
+      .with_entry
+      .joins(ActiveRecord::Base.sanitize_sql_array([
+        "LEFT JOIN exchange_rates ON (
+          exchange_rates.date = entries.date AND
+          exchange_rates.from_currency = trades.currency AND
+          exchange_rates.to_currency = ?
+        )", account.currency
+      ]))
+      .where(security_id: security.id)
+      .where("trades.qty > 0 AND entries.date <= ?", date)
+      .average("trades.price * COALESCE(exchange_rates.rate, 1)")
 
     Money.new(avg_cost || price, currency)
   end
diff --git a/test/models/holding_test.rb b/test/models/holding_test.rb
index 53fddf95..c3cc9a7a 100644
--- a/test/models/holding_test.rb
+++ b/test/models/holding_test.rb
@@ -19,15 +19,26 @@ class HoldingTest < ActiveSupport::TestCase
     assert_in_delta expected_nvda_weight, @nvda.weight, 0.001
   end
 
-  test "calculates simple average cost basis" do
+  test "calculates average cost basis" do
     create_trade(@amzn.security, account: @account, qty: 10, price: 212.00, date: 1.day.ago.to_date)
     create_trade(@amzn.security, account: @account, qty: 15, price: 216.00, date: Date.current)
 
     create_trade(@nvda.security, account: @account, qty: 5, price: 128.00, date: 1.day.ago.to_date)
     create_trade(@nvda.security, account: @account, qty: 30, price: 124.00, date: Date.current)
 
-    assert_equal Money.new((212.0 + 216.0) / 2), @amzn.avg_cost
-    assert_equal Money.new((128.0 + 124.0) / 2), @nvda.avg_cost
+    assert_equal Money.new((212.00 + 216.00).to_d / 2), @amzn.avg_cost
+    assert_equal Money.new((128.00 + 124.00).to_d / 2), @nvda.avg_cost
+  end
+
+  test "calculates average cost basis from another currency" do
+    create_trade(@amzn.security, account: @account, qty: 10, price: 212.00, date: 1.day.ago.to_date, currency: "CAD")
+    create_trade(@amzn.security, account: @account, qty: 15, price: 216.00, date: Date.current, currency: "CAD")
+
+    create_trade(@nvda.security, account: @account, qty: 5, price: 128.00, date: 1.day.ago.to_date, currency: "CAD")
+    create_trade(@nvda.security, account: @account, qty: 30, price: 124.00, date: Date.current, currency: "CAD")
+
+    assert_equal Money.new((212.00 + 216.00).to_d / 2, "CAD").exchange_to("USD", fallback_rate: 1), @amzn.avg_cost
+    assert_equal Money.new((128.00 + 124.00).to_d / 2, "CAD").exchange_to("USD", fallback_rate: 1), @nvda.avg_cost
   end
 
   test "calculates total return trend" do
diff --git a/test/support/entries_test_helper.rb b/test/support/entries_test_helper.rb
index c17b8065..908f9676 100644
--- a/test/support/entries_test_helper.rb
+++ b/test/support/entries_test_helper.rb
@@ -28,20 +28,20 @@ module EntriesTestHelper
     Entry.create! entry_defaults.merge(attributes)
   end
 
-  def create_trade(security, account:, qty:, date:, price: nil)
+  def create_trade(security, account:, qty:, date:, price: nil, currency: "USD")
     trade_price = price || Security::Price.find_by!(security: security, date: date).price
 
     trade = Trade.new \
       qty: qty,
       security: security,
-      price:    trade_price,
-      currency: "USD"
+      price: trade_price,
+      currency: currency
 
     account.entries.create! \
       name: "Trade",
       date: date,
       amount: qty * trade_price,
-      currency: "USD",
+      currency: currency,
       entryable: trade
   end
 end