diff --git a/lib/sis/course_importer.rb b/lib/sis/course_importer.rb
index 85e1506510b..69e42f068d4 100644
--- a/lib/sis/course_importer.rb
+++ b/lib/sis/course_importer.rb
@@ -89,6 +89,9 @@ module SIS
           account = nil
           account = @root_account.all_accounts.where(sis_source_id: account_id).take if account_id.present?
           account ||= @root_account.all_accounts.where(sis_source_id: fallback_account_id).take if fallback_account_id.present?
+          if account_id.present? && !account
+            raise ImportError, "Account not found \"#{account_id}\" for course #{course_id}"
+          end
           course_account_stuck = course.stuck_sis_fields.include?(:account_id)
           unless course_account_stuck
             course.account = account if account
diff --git a/spec/lib/sis/csv/course_importer_spec.rb b/spec/lib/sis/csv/course_importer_spec.rb
index 4cac0c0e361..518a5a88241 100644
--- a/spec/lib/sis/csv/course_importer_spec.rb
+++ b/spec/lib/sis/csv/course_importer_spec.rb
@@ -25,12 +25,12 @@ describe SIS::CSV::CourseImporter do
   it 'should skip bad content' do
     before_count = Course.count
     importer = process_csv_data(
-      "course_id,short_name,long_name,account_id,term_id,status",
-      "C001,Hum101,Humanities,A001,T001,active",
-      ",Hum102,Humanities 2,A001,T001,active",
-      "C003,Hum102,Humanities 2,A001,T001,inactive",
-      "C004,,Humanities 2,A001,T001,active",
-      "C005,Hum102,,A001,T001,active"
+      "course_id,short_name,long_name,term_id,status",
+      "C001,Hum101,Humanities,T001,active",
+      ",Hum102,Humanities 2,T001,active",
+      "C003,Hum102,Humanities 2,T001,inactive",
+      "C004,,Humanities 2,T001,active",
+      "C005,Hum102,,T001,active"
     )
     expect(Course.count).to eq before_count + 1
 
@@ -52,6 +52,15 @@ describe SIS::CSV::CourseImporter do
     expect(course.associated_accounts.map(&:id).sort).to eq [@account.id]
   end
 
+  it "should throw an error when account is not found" do
+    importer = process_csv_data(
+      "course_id,short_name,long_name,account_id,term_id,status",
+      "test_1,TC 101,Test Course 101,VERY_INVALID_ACCOUNT,,active"
+    )
+    errors = importer.errors.map { |r| r.last }
+    expect(errors).to eq ["Account not found \"VERY_INVALID_ACCOUNT\" for course test_1"]
+  end
+
   it "should support term stickiness" do
     process_csv_data_cleanly(
       "term_id,name,status,start_date,end_date",
@@ -642,7 +651,7 @@ describe SIS::CSV::CourseImporter do
   it 'should allow unpublished to be passed for active' do
     process_csv_data_cleanly(
       "course_id,short_name,long_name,account_id,term_id,status",
-      "c1,TC 101,Test Course 1,A001,T001,unpublished"
+      "c1,TC 101,Test Course 1,,T001,unpublished"
     )
     expect(Course.active.where(sis_source_id: 'c1').take).to be_present
   end