diff --git a/app/controllers/valuations_controller.rb b/app/controllers/valuations_controller.rb
index 32ec2df74..5a2966167 100644
--- a/app/controllers/valuations_controller.rb
+++ b/app/controllers/valuations_controller.rb
@@ -7,6 +7,12 @@ class ValuationsController < ApplicationController
 
     @entry = @account.entries.build(entry_params.merge(currency: @account.currency))
 
+    if entry_params[:amount].blank?
+      @error_message = t("valuations.errors.amount_required")
+      render :new, status: :unprocessable_entity
+      return
+    end
+
     @reconciliation_dry_run = @entry.account.create_reconciliation(
       balance: entry_params[:amount],
       date: entry_params[:date],
@@ -21,6 +27,13 @@ class ValuationsController < ApplicationController
     return unless require_account_permission!(@entry.account)
 
     @account = @entry.account
+
+    if entry_params[:amount].blank?
+      @error_message = t("valuations.errors.amount_required")
+      render :show, status: :unprocessable_entity
+      return
+    end
+
     @entry.assign_attributes(entry_params.merge(currency: @account.currency))
 
     @reconciliation_dry_run = @entry.account.update_reconciliation(
diff --git a/app/models/concerns/monetizable.rb b/app/models/concerns/monetizable.rb
index e80fcb5f6..b5eb83886 100644
--- a/app/models/concerns/monetizable.rb
+++ b/app/models/concerns/monetizable.rb
@@ -7,7 +7,7 @@ module Monetizable
         define_method("#{field}_money") do |**args|
           value = self.send(field, **args)
 
-          return nil if value.nil? || monetizable_currency.nil?
+          return nil if value.blank? || monetizable_currency.nil?
 
           Money.new(value, monetizable_currency)
         end
diff --git a/config/locales/views/valuations/en.yml b/config/locales/views/valuations/en.yml
index 7b4ede9d4..f4a55767c 100644
--- a/config/locales/views/valuations/en.yml
+++ b/config/locales/views/valuations/en.yml
@@ -1,6 +1,8 @@
 ---
 en:
   valuations:
+    errors:
+      amount_required: Amount is required
     form:
       amount: Amount
       submit: Add balance update
diff --git a/test/controllers/valuations_controller_test.rb b/test/controllers/valuations_controller_test.rb
index 7827906b8..b7151e606 100644
--- a/test/controllers/valuations_controller_test.rb
+++ b/test/controllers/valuations_controller_test.rb
@@ -50,4 +50,31 @@ class ValuationsControllerTest < ActionDispatch::IntegrationTest
     assert_equal 22000, @entry.amount
     assert_equal "Test notes", @entry.notes
   end
+
+  test "confirm_create with blank amount returns unprocessable entity" do
+    account = accounts(:investment)
+
+    post confirm_create_valuations_url, params: {
+      entry: {
+        amount: "",
+        date: Date.current.to_s,
+        account_id: account.id
+      }
+    }
+
+    assert_response :unprocessable_entity
+    assert_match I18n.t("valuations.errors.amount_required"), response.body
+  end
+
+  test "confirm_update with blank amount returns unprocessable entity" do
+    post confirm_update_valuation_url(@entry), params: {
+      entry: {
+        amount: "",
+        date: Date.current.to_s
+      }
+    }
+
+    assert_response :unprocessable_entity
+    assert_match I18n.t("valuations.errors.amount_required"), response.body
+  end
 end