diff --git a/mypy.ini b/mypy.ini
index 4431c8ff..719fad28 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -3,6 +3,7 @@
 warn_unused_configs = True
 warn_redundant_casts = True
 warn_unused_ignores = True
+no_implicit_reexport = True
 
 [mypy-test.*]
 disallow_untyped_defs = True
diff --git a/pygit2/errors.py b/pygit2/errors.py
index 8bfa8ff5..72a4af39 100644
--- a/pygit2/errors.py
+++ b/pygit2/errors.py
@@ -27,6 +27,8 @@
 from ._pygit2 import GitError
 from .ffi import C, ffi
 
+__all__ = ['GitError']
+
 value_errors = set([C.GIT_EEXISTS, C.GIT_EINVALIDSPEC, C.GIT_EAMBIGUOUS])
 
 
diff --git a/pygit2/ffi.py b/pygit2/ffi.py
index 166227e1..2a5d8604 100644
--- a/pygit2/ffi.py
+++ b/pygit2/ffi.py
@@ -26,3 +26,5 @@
 # Import from pygit2
 from ._libgit2 import ffi  # noqa: F401
 from ._libgit2 import lib as C  # type: ignore # noqa: F401
+
+__all__ = ['C', 'ffi']