diff --git a/asdf/__init__.py b/asdf/__init__.py
index d827e770e..583be9a7e 100644
--- a/asdf/__init__.py
+++ b/asdf/__init__.py
@@ -45,4 +45,12 @@
 class ValidationError(ValidationError):
     pass
 
+try:
+    from astropy.io import fits
+except ImportError:
+    pass
+else:
+    from .fits_embed import _AsdfHDU
+    fits.register_hdu(_AsdfHDU)
+
 open = AsdfFile.open
diff --git a/asdf/fits_embed.py b/asdf/fits_embed.py
index 2cfd66c62..9b6da17a7 100644
--- a/asdf/fits_embed.py
+++ b/asdf/fits_embed.py
@@ -98,9 +98,6 @@ def _summary(self):
         return (self.name, self.ver, self.__class__.__name__, len(self._header))
 
 
-fits.register_hdu(_AsdfHDU)
-
-
 class _FitsBlock(object):
     def __init__(self, hdu):
         self._hdu = hdu