diff --git a/wagtail/wagtailcore/blocks/__init__.py b/wagtail/wagtailcore/blocks/__init__.py
index f58951961..47862b546 100644
--- a/wagtail/wagtailcore/blocks/__init__.py
+++ b/wagtail/wagtailcore/blocks/__init__.py
@@ -558,6 +558,6 @@ class BlockField(forms.Field):
 
 
 # Import block types defined in submodules into the wagtail.wagtailcore.blocks namespace
-from .field import *  # NOQA
+from .field_block import *  # NOQA
 from .list_block import *  # NOQA
-from .stream import *  # NOQA
+from .stream_block import *  # NOQA
diff --git a/wagtail/wagtailcore/blocks/field.py b/wagtail/wagtailcore/blocks/field_block.py
similarity index 100%
rename from wagtail/wagtailcore/blocks/field.py
rename to wagtail/wagtailcore/blocks/field_block.py
diff --git a/wagtail/wagtailcore/blocks/stream.py b/wagtail/wagtailcore/blocks/stream_block.py
similarity index 100%
rename from wagtail/wagtailcore/blocks/stream.py
rename to wagtail/wagtailcore/blocks/stream_block.py