diff --git a/skimage/io/_plugins/freeimage_plugin.py b/skimage/io/_plugins/freeimage_plugin.py
index 5d023909..9cb9c467 100644
--- a/skimage/io/_plugins/freeimage_plugin.py
+++ b/skimage/io/_plugins/freeimage_plugin.py
@@ -153,20 +153,20 @@ class FI_TYPES(object):
         }
 
     fi_types = {
-        (numpy.uint8, 1): FIT_BITMAP,
-        (numpy.uint8, 3): FIT_BITMAP,
-        (numpy.uint8, 4): FIT_BITMAP,
-        (numpy.uint16, 1): FIT_UINT16,
-        (numpy.int16, 1): FIT_INT16,
-        (numpy.uint32, 1): FIT_UINT32,
-        (numpy.int32, 1): FIT_INT32,
-        (numpy.float32, 1): FIT_FLOAT,
-        (numpy.float64, 1): FIT_DOUBLE,
-        (numpy.complex128, 1): FIT_COMPLEX,
-        (numpy.uint16, 3): FIT_RGB16,
-        (numpy.uint16, 4): FIT_RGBA16,
-        (numpy.float32, 3): FIT_RGBF,
-        (numpy.float32, 4): FIT_RGBAF
+        (numpy.dtype('uint8'), 1): FIT_BITMAP,
+        (numpy.dtype('uint8'), 3): FIT_BITMAP,
+        (numpy.dtype('uint8'), 4): FIT_BITMAP,
+        (numpy.dtype('uint16'), 1): FIT_UINT16,
+        (numpy.dtype('int16'), 1): FIT_INT16,
+        (numpy.dtype('uint32'), 1): FIT_UINT32,
+        (numpy.dtype('int32'), 1): FIT_INT32,
+        (numpy.dtype('float32'), 1): FIT_FLOAT,
+        (numpy.dtype('float64'), 1): FIT_DOUBLE,
+        (numpy.dtype('complex128'), 1): FIT_COMPLEX,
+        (numpy.dtype('uint16'), 3): FIT_RGB16,
+        (numpy.dtype('uint16'), 4): FIT_RGBA16,
+        (numpy.dtype('float32'), 3): FIT_RGBF,
+        (numpy.dtype('float32'), 4): FIT_RGBAF
         }
 
     extra_dims = {
@@ -608,7 +608,7 @@ def _array_to_bitmap(array):
     else:
         n_channels = shape[0]
     try:
-        fi_type = FI_TYPES.fi_types[(dtype.type, n_channels)]
+        fi_type = FI_TYPES.fi_types[(dtype, n_channels)]
     except KeyError:
         raise ValueError('Cannot write arrays of given type and shape.')