diff --git a/tests/utils/test_preprocess.py b/tests/utils/test_preprocess.py
index 4f425b16..2626cedb 100644
--- a/tests/utils/test_preprocess.py
+++ b/tests/utils/test_preprocess.py
@@ -280,7 +280,7 @@ class PreprocessTestCase(TestCase):
         self.assertIs(c_ret, good_c)
 
         with self.assertRaises(TypeError) as e:
-            foo(good_a, arange(3), good_c)
+            foo(good_a, arange(3, dtype='int64'), good_c)
 
         expected_message = (
             "{qualname}() expected a value with dtype 'datetime64[ns]'"
diff --git a/zipline/data/_adjustments.pyx b/zipline/data/_adjustments.pyx
index b53474f2..5fded76b 100644
--- a/zipline/data/_adjustments.pyx
+++ b/zipline/data/_adjustments.pyx
@@ -18,6 +18,7 @@ from cpython cimport (
 )
 
 from numpy import (
+    int64,
     uint32,
     zeros,
 )
@@ -208,7 +209,7 @@ cpdef load_adjustments_from_sqlite(object adjustments_db,  # sqlite3.Connection
         dict col_adjustments
 
     cdef ndarray[int64_t, ndim=1] _dates_seconds = \
-        dates.values.astype('datetime64[s]').view(int)
+        dates.values.astype('datetime64[s]').view(int64)
 
     # Pre-populate date index cache.
     for i, dt in enumerate(_dates_seconds):
diff --git a/zipline/data/us_equity_pricing.py b/zipline/data/us_equity_pricing.py
index 6b15f013..8d508b9e 100644
--- a/zipline/data/us_equity_pricing.py
+++ b/zipline/data/us_equity_pricing.py
@@ -302,8 +302,9 @@ class DailyBarWriterFromCSVs(BcolzDailyBarWriter):
             return array.astype(uint32)
         elif colname == 'day':
             nanos_per_second = (1000 * 1000 * 1000)
-            self.check_uint_safe(arrmax.view(int) / nanos_per_second, colname)
-            return (array.view(int) / nanos_per_second).astype(uint32)
+            self.check_uint_safe(arrmax.view(int64) / nanos_per_second,
+                                 colname)
+            return (array.view(int64) / nanos_per_second).astype(uint32)
 
     @staticmethod
     def check_uint_safe(value, colname):
diff --git a/zipline/pipeline/loaders/synthetic.py b/zipline/pipeline/loaders/synthetic.py
index 1d983a53..a212b2c0 100644
--- a/zipline/pipeline/loaders/synthetic.py
+++ b/zipline/pipeline/loaders/synthetic.py
@@ -173,7 +173,8 @@ class SeededRandomLoader(PrecomputedLoader):
         """
         Return uniformly-distributed integers between 0 and 100.
         """
-        return self.state.random_integers(low=0, high=100, size=shape)
+        return (self.state.random_integers(low=0, high=100, size=shape)
+                .astype('int64'))  # default is system int
 
     def _datetime_values(self, shape):
         """