diff --git a/esrally/track/params.py b/esrally/track/params.py
index 9c131dab8..c15ce0130 100644
--- a/esrally/track/params.py
+++ b/esrally/track/params.py
@@ -554,9 +554,11 @@ def __init__(self, corpora, partition_index, total_partitions, batch_size, bulk_
         self.ingest_percentage = ingest_percentage
         self.id_conflicts = id_conflicts
         self.pipeline = pipeline
+        # this is only intended for unit-testing
+        create_reader = original_params.pop("__create_reader", create_default_reader)
         self.internal_params = bulk_data_based(total_partitions, partition_index, corpora, batch_size,
                                                bulk_size, id_conflicts, conflict_probability, on_conflict, recency,
-                                               pipeline, original_params)
+                                               pipeline, original_params, create_reader)
         self.current_bulk = 0
         all_bulks = number_of_bulks(self.corpora, self.partition_index, self.total_partitions, self.bulk_size)
         self.total_bulks = math.ceil((all_bulks * self.ingest_percentage) / 100)
@@ -566,6 +568,10 @@ def partition(self, partition_index, total_partitions):
         raise exceptions.RallyError("Cannot partition a PartitionBulkIndexParamSource further")
 
     def params(self):
+        # self.internal_params always reads all files. This is necessary to ensure we terminate early in case
+        # the user has specified ingest percentage.
+        if self.current_bulk == self.total_bulks:
+            raise StopIteration
         self.current_bulk += 1
         return next(self.internal_params)
 
diff --git a/tests/track/params_test.py b/tests/track/params_test.py
index ac0a0a133..d7a686617 100644
--- a/tests/track/params_test.py
+++ b/tests/track/params_test.py
@@ -23,6 +23,28 @@
 from esrally.utils import io
 
 
+class StaticBulkReader:
+    def __init__(self, index_name, type_name, bulks):
+        self.index_name = index_name
+        self.type_name = type_name
+        self.bulks = iter(bulks)
+
+    def __enter__(self):
+        return self
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        batch = []
+        bulk = next(self.bulks)
+        batch.append((len(bulk), bulk))
+        return self.index_name, self.type_name, batch
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        return False
+
+
 class SliceTests(TestCase):
     def test_slice_with_source_larger_than_slice(self):
         source = params.Slice(io.StringAsFileSource, 2, 5)
@@ -865,6 +887,27 @@ def test_ingests_all_documents_by_default(self):
         self.assertEqual(100, partition.total_bulks)
 
     def test_restricts_number_of_bulks_if_required(self):
+        def create_unit_test_reader(*args):
+            return StaticBulkReader("idx", "doc", bulks=[
+                ['{"location" : [-0.1485188, 51.5250666]}'],
+                ['{"location" : [-0.1479949, 51.5252071]}'],
+                ['{"location" : [-0.1458559, 51.5289059]}'],
+                ['{"location" : [-0.1498551, 51.5282564]}'],
+                ['{"location" : [-0.1487043, 51.5254843]}'],
+                ['{"location" : [-0.1533367, 51.5261779]}'],
+                ['{"location" : [-0.1543018, 51.5262398]}'],
+                ['{"location" : [-0.1522118, 51.5266564]}'],
+                ['{"location" : [-0.1529092, 51.5263360]}'],
+                ['{"location" : [-0.1537008, 51.5265365]}'],
+            ])
+
+        def schedule(param_source):
+            while True:
+                try:
+                    yield param_source.params()
+                except StopIteration:
+                    return
+
         corpora = [
             track.DocumentCorpus(name="default", documents=[
                 track.Documents(source_format=track.Documents.SOURCE_FORMAT_BULK,
@@ -886,12 +929,14 @@ def test_restricts_number_of_bulks_if_required(self):
             track=track.Track(name="unit-test", corpora=corpora),
             params={
                 "bulk-size": 10000,
-                "ingest-percentage": 2.5
+                "ingest-percentage": 2.5,
+                "__create_reader": create_unit_test_reader
             })
 
         partition = source.partition(0, 1)
         # should issue three bulks of size 10.000
         self.assertEqual(3, partition.total_bulks)
+        self.assertEqual(3, len(list(schedule(partition))))
 
     def test_create_with_conflict_probability_zero(self):
         params.BulkIndexParamSource(track=track.Track(name="unit-test"), params={
@@ -932,31 +977,11 @@ def test_create_with_conflict_probability_not_numeric(self):
 
 
 class BulkDataGeneratorTests(TestCase):
-    class TestBulkReader:
-        def __init__(self, index_name, type_name, bulks):
-            self.index_name = index_name
-            self.type_name = type_name
-            self.bulks = iter(bulks)
-
-        def __enter__(self):
-            return self
-
-        def __iter__(self):
-            return self
-
-        def __next__(self):
-            batch = []
-            bulk = next(self.bulks)
-            batch.append((len(bulk), bulk))
-            return self.index_name, self.type_name, batch
-
-        def __exit__(self, exc_type, exc_val, exc_tb):
-            return False
 
     @classmethod
     def create_test_reader(cls, batches):
         def inner_create_test_reader(docs, *args):
-            return BulkDataGeneratorTests.TestBulkReader(docs.target_index, docs.target_type, batches)
+            return StaticBulkReader(docs.target_index, docs.target_type, batches)
 
         return inner_create_test_reader