diff --git a/tensorflow/g3doc/api_docs/python/state_ops.md b/tensorflow/g3doc/api_docs/python/state_ops.md
index 7a183236855..504ecc7e243 100644
--- a/tensorflow/g3doc/api_docs/python/state_ops.md
+++ b/tensorflow/g3doc/api_docs/python/state_ops.md
@@ -1164,7 +1164,7 @@ then all its sub-scopes become reusing as well.
 
 - - -
 
-### `tf.constant_initializer(value=0.0)` {#constant_initializer}
+### `tf.constant_initializer(value=0.0, dtype=tf.float32)` {#constant_initializer}
 
 Returns an initializer that generates tensors with a single value.
 
@@ -1173,15 +1173,21 @@ Returns an initializer that generates tensors with a single value.
 
 *  <b>`value`</b>: A Python scalar. All elements of the initialized variable
     will be set to this value.
+*  <b>`dtype`</b>: The data type. Only floating point types are supported.
 
 ##### Returns:
 
   An initializer that generates tensors with a single value.
 
+##### Raises:
+
+
+*  <b>`ValueError`</b>: if `dtype` is not a floating point type.
+
 
 - - -
 
-### `tf.random_normal_initializer(mean=0.0, stddev=1.0, seed=None)` {#random_normal_initializer}
+### `tf.random_normal_initializer(mean=0.0, stddev=1.0, seed=None, dtype=tf.float32)` {#random_normal_initializer}
 
 Returns an initializer that generates tensors with a normal distribution.
 
@@ -1195,15 +1201,21 @@ Returns an initializer that generates tensors with a normal distribution.
 *  <b>`seed`</b>: A Python integer. Used to create random seeds. See
     [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
     for behavior.
+*  <b>`dtype`</b>: The data type. Only floating point types are supported.
 
 ##### Returns:
 
   An initializer that generates tensors with a normal distribution.
 
+##### Raises:
+
+
+*  <b>`ValueError`</b>: if `dtype` is not a floating point type.
+
 
 - - -
 
-### `tf.truncated_normal_initializer(mean=0.0, stddev=1.0, seed=None)` {#truncated_normal_initializer}
+### `tf.truncated_normal_initializer(mean=0.0, stddev=1.0, seed=None, dtype=tf.float32)` {#truncated_normal_initializer}
 
 Returns an initializer that generates a truncated normal distribution.
 
@@ -1222,16 +1234,22 @@ neural network weights and filters.
 *  <b>`seed`</b>: A Python integer. Used to create random seeds. See
     [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
     for behavior.
+*  <b>`dtype`</b>: The data type. Only floating point types are supported.
 
 ##### Returns:
 
   An initializer that generates tensors with a truncated normal
   distribution.
 
+##### Raises:
+
+
+*  <b>`ValueError`</b>: if `dtype` is not a floating point type.
+
 
 - - -
 
-### `tf.random_uniform_initializer(minval=0.0, maxval=1.0, seed=None)` {#random_uniform_initializer}
+### `tf.random_uniform_initializer(minval=0.0, maxval=1.0, seed=None, dtype=tf.float32)` {#random_uniform_initializer}
 
 Returns an initializer that generates tensors with a uniform distribution.
 
@@ -1245,15 +1263,21 @@ Returns an initializer that generates tensors with a uniform distribution.
 *  <b>`seed`</b>: A Python integer. Used to create random seeds. See
     [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
     for behavior.
+*  <b>`dtype`</b>: The data type. Only floating point types are supported.
 
 ##### Returns:
 
   An initializer that generates tensors with a uniform distribution.
 
+##### Raises:
+
+
+*  <b>`ValueError`</b>: if `dtype` is not a floating point type.
+
 
 - - -
 
-### `tf.uniform_unit_scaling_initializer(factor=1.0, seed=None)` {#uniform_unit_scaling_initializer}
+### `tf.uniform_unit_scaling_initializer(factor=1.0, seed=None, dtype=tf.float32)` {#uniform_unit_scaling_initializer}
 
 Returns an initializer that generates tensors without scaling variance.
 
@@ -1279,11 +1303,17 @@ numerically computed: for a linear layer it's 1.0, relu: ~1.43, tanh: ~1.15.
 *  <b>`seed`</b>: A Python integer. Used to create random seeds. See
     [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
     for behavior.
+*  <b>`dtype`</b>: The data type. Only floating point types are supported.
 
 ##### Returns:
 
   An initializer that generates tensors with unit variance.
 
+##### Raises:
+
+
+*  <b>`ValueError`</b>: if `dtype` is not a floating point type.
+
 
 - - -
 
diff --git a/tensorflow/python/kernel_tests/init_ops_test.py b/tensorflow/python/kernel_tests/init_ops_test.py
index c0eef1edc80..145058579ea 100644
--- a/tensorflow/python/kernel_tests/init_ops_test.py
+++ b/tensorflow/python/kernel_tests/init_ops_test.py
@@ -93,87 +93,115 @@ class RandomNormalInitializationTest(tf.test.TestCase):
 
   def testInitializerIdentical(self):
     for use_gpu in [False, True]:
-      init1 = tf.random_normal_initializer(0.0, 1.0, seed=1)
-      init2 = tf.random_normal_initializer(0.0, 1.0, seed=1)
-      self.assertTrue(identicaltest(self, init1, init2, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.random_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.random_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        self.assertTrue(identicaltest(self, init1, init2, use_gpu))
 
   def testInitializerDifferent(self):
     for use_gpu in [False, True]:
-      init1 = tf.random_normal_initializer(0.0, 1.0, seed=1)
-      init2 = tf.random_normal_initializer(0.0, 1.0, seed=2)
-      self.assertFalse(identicaltest(self, init1, init2, use_gpu=use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.random_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.random_normal_initializer(0.0, 1.0, seed=2, dtype=dtype)
+        self.assertFalse(identicaltest(self, init1, init2, use_gpu=use_gpu))
 
   def testDuplicatedInitializer(self):
     for use_gpu in [False, True]:
       init = tf.random_normal_initializer(0.0, 1.0)
       self.assertFalse(duplicated_initializer(self, init, use_gpu, 1))
 
+  def testInvalidDataType(self):
+    self.assertRaises(
+        ValueError,
+        tf.random_normal_initializer, 0.0, 1.0, dtype=tf.string)
+
 
 class TruncatedNormalInitializationTest(tf.test.TestCase):
 
   def testInitializerIdentical(self):
     for use_gpu in [False, True]:
-      init1 = tf.truncated_normal_initializer(0.0, 1.0, seed=1)
-      init2 = tf.truncated_normal_initializer(0.0, 1.0, seed=1)
-      self.assertTrue(identicaltest(self, init1, init2, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.truncated_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.truncated_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        self.assertTrue(identicaltest(self, init1, init2, use_gpu))
 
   def testInitializerDifferent(self):
     for use_gpu in [False, True]:
-      init1 = tf.truncated_normal_initializer(0.0, 1.0, seed=1)
-      init2 = tf.truncated_normal_initializer(0.0, 1.0, seed=2)
-      self.assertFalse(identicaltest(self, init1, init2, use_gpu=use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.truncated_normal_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.truncated_normal_initializer(0.0, 1.0, seed=2, dtype=dtype)
+        self.assertFalse(identicaltest(self, init1, init2, use_gpu=use_gpu))
 
   def testDuplicatedInitializer(self):
     for use_gpu in [False, True]:
       init = tf.truncated_normal_initializer(0.0, 1.0)
       self.assertFalse(duplicated_initializer(self, init, use_gpu, 1))
 
+  def testInvalidDataType(self):
+    self.assertRaises(
+        ValueError,
+        tf.truncated_normal_initializer, 0.0, 1.0, dtype=tf.string)
+
 
 class RandomUniformInitializationTest(tf.test.TestCase):
 
   def testInitializerIdentical(self):
     for use_gpu in [False, True]:
-      init1 = tf.random_uniform_initializer(0.0, 1.0, seed=1)
-      init2 = tf.random_uniform_initializer(0.0, 1.0, seed=1)
-      self.assertTrue(identicaltest(self, init1, init2, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.random_uniform_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.random_uniform_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        self.assertTrue(identicaltest(self, init1, init2, use_gpu))
 
   def testInitializerDifferent(self):
     for use_gpu in [False, True]:
-      init1 = tf.random_uniform_initializer(0.0, 1.0, seed=1)
-      init2 = tf.random_uniform_initializer(0.0, 1.0, seed=2)
-      self.assertFalse(identicaltest(self, init1, init2, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.random_uniform_initializer(0.0, 1.0, seed=1, dtype=dtype)
+        init2 = tf.random_uniform_initializer(0.0, 1.0, seed=2, dtype=dtype)
+        self.assertFalse(identicaltest(self, init1, init2, use_gpu))
 
   def testDuplicatedInitializer(self):
     for use_gpu in [False, True]:
       init = tf.random_uniform_initializer(0.0, 1.0)
       self.assertFalse(duplicated_initializer(self, init, use_gpu, 1))
 
+  def testInvalidDataType(self):
+    self.assertRaises(
+        ValueError,
+        tf.random_uniform_initializer, 0.0, 1.0, dtype=tf.string)
+
 
 class UniformUnitScalingInitializationTest(tf.test.TestCase):
 
   def testInitializerIdentical(self):
     for use_gpu in [False, True]:
-      init1 = tf.uniform_unit_scaling_initializer(seed=1)
-      init2 = tf.uniform_unit_scaling_initializer(seed=1)
-      self.assertTrue(identicaltest(self, init1, init2, use_gpu))
-      init3 = tf.uniform_unit_scaling_initializer(1.5, seed=1)
-      init4 = tf.uniform_unit_scaling_initializer(1.5, seed=1)
-      self.assertTrue(identicaltest(self, init3, init4, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.uniform_unit_scaling_initializer(seed=1, dtype=dtype)
+        init2 = tf.uniform_unit_scaling_initializer(seed=1, dtype=dtype)
+        self.assertTrue(identicaltest(self, init1, init2, use_gpu))
+        init3 = tf.uniform_unit_scaling_initializer(1.5, seed=1, dtype=dtype)
+        init4 = tf.uniform_unit_scaling_initializer(1.5, seed=1, dtype=dtype)
+        self.assertTrue(identicaltest(self, init3, init4, use_gpu))
 
   def testInitializerDifferent(self):
     for use_gpu in [False, True]:
-      init1 = tf.uniform_unit_scaling_initializer(seed=1)
-      init2 = tf.uniform_unit_scaling_initializer(seed=2)
-      init3 = tf.uniform_unit_scaling_initializer(1.5, seed=1)
-      self.assertFalse(identicaltest(self, init1, init2, use_gpu))
-      self.assertFalse(identicaltest(self, init1, init3, use_gpu))
-      self.assertFalse(identicaltest(self, init2, init3, use_gpu))
+      for dtype in [tf.float32, tf.float64]:
+        init1 = tf.uniform_unit_scaling_initializer(seed=1, dtype=dtype)
+        init2 = tf.uniform_unit_scaling_initializer(seed=2, dtype=dtype)
+        init3 = tf.uniform_unit_scaling_initializer(1.5, seed=1, dtype=dtype)
+        self.assertFalse(identicaltest(self, init1, init2, use_gpu))
+        self.assertFalse(identicaltest(self, init1, init3, use_gpu))
+        self.assertFalse(identicaltest(self, init2, init3, use_gpu))
 
   def testDuplicatedInitializer(self):
     for use_gpu in [False, True]:
       init = tf.uniform_unit_scaling_initializer()
       self.assertFalse(duplicated_initializer(self, init, use_gpu, 1))
 
+  def testInvalidDataType(self):
+    self.assertRaises(
+        ValueError,
+        tf.uniform_unit_scaling_initializer, dtype=tf.string)
+
 
 class RandomWalkShapeTest(tf.test.TestCase):
 
diff --git a/tensorflow/python/ops/init_ops.py b/tensorflow/python/ops/init_ops.py
index 8c52a232cb2..eda688b1a9e 100644
--- a/tensorflow/python/ops/init_ops.py
+++ b/tensorflow/python/ops/init_ops.py
@@ -27,22 +27,46 @@ from tensorflow.python.ops import nn_ops
 from tensorflow.python.ops import random_ops
 
 
-# TODO(mrry): PEP8 these.
-def constant_initializer(value=0.0):
+def _assert_float_dtype(dtype):
+  """Validate and return floating point type based on `dtype`.
+
+  `dtype` must be a floating point type.
+
+  Args:
+    dtype: The data type to validate.
+
+  Returns:
+    Validated type.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
+  """
+  if not dtype.is_floating:
+    raise ValueError("Expected floating point type, got %s." % dtype)
+  return dtype
+
+
+def constant_initializer(value=0.0, dtype=dtypes.float32):
   """Returns an initializer that generates tensors with a single value.
 
   Args:
     value: A Python scalar. All elements of the initialized variable
       will be set to this value.
+    dtype: The data type. Only floating point types are supported.
 
   Returns:
     An initializer that generates tensors with a single value.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
   """
-  def _initializer(shape, dtype=dtypes.float32):
+  def _initializer(shape, dtype=_assert_float_dtype(dtype)):
     return constant_op.constant(value, dtype=dtype, shape=shape)
   return _initializer
 
-def random_uniform_initializer(minval=0.0, maxval=1.0, seed=None):
+
+def random_uniform_initializer(minval=0.0, maxval=1.0, seed=None,
+                               dtype=dtypes.float32):
   """Returns an initializer that generates tensors with a uniform distribution.
 
   Args:
@@ -53,15 +77,21 @@ def random_uniform_initializer(minval=0.0, maxval=1.0, seed=None):
     seed: A Python integer. Used to create random seeds. See
       [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
       for behavior.
+    dtype: The data type. Only floating point types are supported.
 
   Returns:
     An initializer that generates tensors with a uniform distribution.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
   """
-  def _initializer(shape, dtype=dtypes.float32):
+  def _initializer(shape, dtype=_assert_float_dtype(dtype)):
     return random_ops.random_uniform(shape, minval, maxval, dtype, seed=seed)
   return _initializer
 
-def random_normal_initializer(mean=0.0, stddev=1.0, seed=None):
+
+def random_normal_initializer(mean=0.0, stddev=1.0, seed=None,
+                              dtype=dtypes.float32):
   """Returns an initializer that generates tensors with a normal distribution.
 
   Args:
@@ -72,15 +102,21 @@ def random_normal_initializer(mean=0.0, stddev=1.0, seed=None):
     seed: A Python integer. Used to create random seeds. See
       [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
       for behavior.
+    dtype: The data type. Only floating point types are supported.
 
   Returns:
     An initializer that generates tensors with a normal distribution.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
   """
-  def _initializer(shape, dtype=dtypes.float32):
+  def _initializer(shape, dtype=_assert_float_dtype(dtype)):
     return random_ops.random_normal(shape, mean, stddev, dtype, seed=seed)
   return _initializer
 
-def truncated_normal_initializer(mean=0.0, stddev=1.0, seed=None):
+
+def truncated_normal_initializer(mean=0.0, stddev=1.0, seed=None,
+                                 dtype=dtypes.float32):
   """Returns an initializer that generates a truncated normal distribution.
 
   These values are similar to values from a `random_normal_initializer`
@@ -96,16 +132,22 @@ def truncated_normal_initializer(mean=0.0, stddev=1.0, seed=None):
     seed: A Python integer. Used to create random seeds. See
       [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
       for behavior.
+    dtype: The data type. Only floating point types are supported.
 
   Returns:
     An initializer that generates tensors with a truncated normal
     distribution.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
   """
-  def _initializer(shape, dtype=dtypes.float32):
+  def _initializer(shape, dtype=_assert_float_dtype(dtype)):
     return random_ops.truncated_normal(shape, mean, stddev, dtype, seed=seed)
   return _initializer
 
-def uniform_unit_scaling_initializer(factor=1.0, seed=None):
+
+def uniform_unit_scaling_initializer(factor=1.0, seed=None,
+                                     dtype=dtypes.float32):
   """Returns an initializer that generates tensors without scaling variance.
 
   When initializing a deep network, it is in principle advantageous to keep
@@ -128,11 +170,15 @@ def uniform_unit_scaling_initializer(factor=1.0, seed=None):
     seed: A Python integer. Used to create random seeds. See
       [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)
       for behavior.
+    dtype: The data type. Only floating point types are supported.
 
   Returns:
     An initializer that generates tensors with unit variance.
+
+  Raises:
+    ValueError: if `dtype` is not a floating point type.
   """
-  def _initializer(shape, dtype=dtypes.float32):
+  def _initializer(shape, dtype=_assert_float_dtype(dtype)):
     input_size = 1.0
     # Estimating input size is not possible to do perfectly, but we try.
     # The estimate, obtained by multiplying all dimensions but the last one,