diff --git a/src/scikit_build_core/build/_editable.py b/src/scikit_build_core/build/_editable.py
index 9a1cca1b..f92d203f 100644
--- a/src/scikit_build_core/build/_editable.py
+++ b/src/scikit_build_core/build/_editable.py
@@ -70,6 +70,7 @@ def libdir_to_installed(libdir: Path) -> dict[str, str]:
     Convert a mapping of files to modules to a mapping of modules to installed files.
     """
     return {
-        path_to_module(v.relative_to(libdir)): str(v.relative_to(libdir))
+        path_to_module(pth): str(pth)
         for v in scantree(libdir)
+        if is_valid_module(pth := v.relative_to(libdir))
     }
diff --git a/src/scikit_build_core/build/_pathutil.py b/src/scikit_build_core/build/_pathutil.py
index 9242290a..3bf020e3 100644
--- a/src/scikit_build_core/build/_pathutil.py
+++ b/src/scikit_build_core/build/_pathutil.py
@@ -28,7 +28,9 @@ def scantree(path: Path) -> Generator[Path, None, None]:
 
 
 def path_to_module(path: Path) -> str:
-    path = path.with_name(path.name.split(".", 1)[0])
+    name, _, _ = path.name.partition(".")
+    assert name, f"Empty name should be filtered by is_valid_module first, got {path}"
+    path = path.with_name(name)
     if path.name == "__init__":
         path = path.parent
     return ".".join(path.parts)
diff --git a/tests/packages/navigate_editable/CMakeLists.txt b/tests/packages/navigate_editable/CMakeLists.txt
index 2c7f3e2e..13420b6f 100644
--- a/tests/packages/navigate_editable/CMakeLists.txt
+++ b/tests/packages/navigate_editable/CMakeLists.txt
@@ -12,6 +12,7 @@ python_add_library(c_module MODULE src/shared_pkg/c_module.c WITH_SOABI)
 set(CMakeVar "Some_value_C")
 configure_file(src/shared_pkg/data/generated.txt.in
                shared_pkg/data/c_generated.txt)
+configure_file(src/shared_pkg/data/generated.txt.in shared_pkg/data/.hidden)
 
 install(
   TARGETS c_module
@@ -19,3 +20,5 @@ install(
   COMPONENT PythonModule)
 install(FILES ${PROJECT_BINARY_DIR}/shared_pkg/data/c_generated.txt
         DESTINATION shared_pkg/data/)
+install(FILES ${PROJECT_BINARY_DIR}/shared_pkg/data/.hidden
+        DESTINATION shared_pkg/data/)