diff --git a/asdf/core/__init__.py b/asdf/_core/__init__.py
similarity index 100%
rename from asdf/core/__init__.py
rename to asdf/_core/__init__.py
diff --git a/asdf/core/_converters/__init__.py b/asdf/_core/_converters/__init__.py
similarity index 100%
rename from asdf/core/_converters/__init__.py
rename to asdf/_core/_converters/__init__.py
diff --git a/asdf/core/_converters/complex.py b/asdf/_core/_converters/complex.py
similarity index 100%
rename from asdf/core/_converters/complex.py
rename to asdf/_core/_converters/complex.py
diff --git a/asdf/core/_converters/constant.py b/asdf/_core/_converters/constant.py
similarity index 100%
rename from asdf/core/_converters/constant.py
rename to asdf/_core/_converters/constant.py
diff --git a/asdf/core/_converters/external_reference.py b/asdf/_core/_converters/external_reference.py
similarity index 100%
rename from asdf/core/_converters/external_reference.py
rename to asdf/_core/_converters/external_reference.py
diff --git a/asdf/core/_converters/integer.py b/asdf/_core/_converters/integer.py
similarity index 100%
rename from asdf/core/_converters/integer.py
rename to asdf/_core/_converters/integer.py
diff --git a/asdf/core/_converters/ndarray.py b/asdf/_core/_converters/ndarray.py
similarity index 100%
rename from asdf/core/_converters/ndarray.py
rename to asdf/_core/_converters/ndarray.py
diff --git a/asdf/core/_converters/reference.py b/asdf/_core/_converters/reference.py
similarity index 100%
rename from asdf/core/_converters/reference.py
rename to asdf/_core/_converters/reference.py
diff --git a/asdf/core/_converters/tree.py b/asdf/_core/_converters/tree.py
similarity index 100%
rename from asdf/core/_converters/tree.py
rename to asdf/_core/_converters/tree.py
diff --git a/asdf/core/_extensions.py b/asdf/_core/_extensions.py
similarity index 100%
rename from asdf/core/_extensions.py
rename to asdf/_core/_extensions.py
diff --git a/asdf/core/_integration.py b/asdf/_core/_integration.py
similarity index 100%
rename from asdf/core/_integration.py
rename to asdf/_core/_integration.py
diff --git a/asdf/core/_validators/__init__.py b/asdf/_core/_validators/__init__.py
similarity index 100%
rename from asdf/core/_validators/__init__.py
rename to asdf/_core/_validators/__init__.py
diff --git a/asdf/core/_validators/ndarray.py b/asdf/_core/_validators/ndarray.py
similarity index 100%
rename from asdf/core/_validators/ndarray.py
rename to asdf/_core/_validators/ndarray.py
diff --git a/asdf/_tests/core/tests/test_integration.py b/asdf/_tests/core/tests/test_integration.py
index b808dc729..1ef979978 100644
--- a/asdf/_tests/core/tests/test_integration.py
+++ b/asdf/_tests/core/tests/test_integration.py
@@ -2,7 +2,7 @@
 import yaml
 
 import asdf
-from asdf.core._integration import get_extensions, get_json_schema_resource_mappings
+from asdf._core._integration import get_extensions, get_json_schema_resource_mappings
 
 
 @pytest.mark.parametrize(
diff --git a/asdf/_tests/test_config.py b/asdf/_tests/test_config.py
index 0b90ec14a..0e082deb3 100644
--- a/asdf/_tests/test_config.py
+++ b/asdf/_tests/test_config.py
@@ -5,7 +5,7 @@
 
 import asdf
 from asdf import get_config
-from asdf.core._integration import get_json_schema_resource_mappings
+from asdf._core._integration import get_json_schema_resource_mappings
 from asdf.extension import ExtensionProxy
 from asdf.resource import ResourceMappingProxy
 
diff --git a/pyproject.toml b/pyproject.toml
index 3f954c247..98c45744f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -55,8 +55,8 @@ tests = [
 'repository' = 'https://github.com/asdf-format/asdf'
 'tracker' = 'https://github.com/asdf-format/asdf/issues'
 [project.entry-points]
-'asdf.extensions' = {asdf = 'asdf.core._integration:get_extensions'}
-'asdf.resource_mappings' = {asdf = 'asdf.core._integration:get_json_schema_resource_mappings'}
+'asdf.extensions' = {asdf = 'asdf._core._integration:get_extensions'}
+'asdf.resource_mappings' = {asdf = 'asdf._core._integration:get_json_schema_resource_mappings'}
 asdf_extensions = {builtin = 'asdf.extension._legacy:BuiltinExtension'}
 console_scripts = {asdftool = 'asdf.commands.main:main'}
 pytest11 = {asdf_schema_tester = 'pytest_asdf.plugin'}