diff --git a/docs/api.md b/docs/api.md
index 9e7f0da..26c697b 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -39,7 +39,7 @@ and application-specific output can still contain sensitive data.
 | `base_url` / `base_url_env` | Unset | Existing HTTP(S) URL or its environment-variable name |
 | `config` | Generated | Compiled ESM Playwright config |
 | `data` | `[]` | Additional runtime inputs |
-| `runtime_only` | `True` | Exclude source/type/debug files from compiled inputs and prune maps from built directories and shell assets in the test target's repository; explicit `data` stays unfiltered. Set `False` to retain source/debug inputs. See [runtime-only inputs](e2e.md#runtime-only-inputs). |
+| `runtime_only` | `True` | Exclude source/type/debug files from compiled inputs and prune maps from built directories and shell assets in the test target's repository; npm packages and explicit `data` stay unfiltered. Set `False` to retain source/debug inputs. See [runtime-only inputs](e2e.md#runtime-only-inputs). |
 | `env` / `env_inherit` | `{}` / `[]` | Explicit values / inherited names; inheritance host-only |
 | `network_origins` / `network_origins_env` | `[]` / `[]` | Extra allowed origins / env names containing them; host-only |
 | `args` | `[]` | Default selection flags; see below |
diff --git a/docs/e2e.md b/docs/e2e.md
index 2421ad9..f050929 100644
--- a/docs/e2e.md
+++ b/docs/e2e.md
@@ -217,8 +217,11 @@ remain. Directory artifacts owned by the test's repository are copied without
 aliases. This also applies to built `browser_shell` assets. Other files within
 directories are preserved. A map-only change may rerun the copy action without
 invalidating the browser result when the projected contents are identical.
-Other repositories' files, browser/runtime packages, explicit `data`, and snapshot
-inputs are not filtered. Explicit `data` wins when the same directory also appears
+Other repositories' files, npm packages under `node_modules`, browser/runtime
+packages, explicit `data`, and snapshot inputs are not filtered. npm package trees
+retain their original artifact paths so Node can resolve imports from real
+compiled-file paths without relying on previously materialized build outputs.
+Explicit `data` wins when the same directory also appears
 in compiled inputs. Declare a
 source file or map in `data` if the test intentionally reads it.
 
diff --git a/internal/runtime_inputs.bzl b/internal/runtime_inputs.bzl
index 1c0dcd2..88170d4 100644
--- a/internal/runtime_inputs.bzl
+++ b/internal/runtime_inputs.bzl
@@ -3,14 +3,18 @@
 load("@bazel_lib//lib:copy_to_directory.bzl", "copy_to_directory_bin_action")
 load("@bazel_lib//lib:paths.bzl", "to_repository_relative_path")
 
+def _is_package_file(ctx, file):
+    # Node resolves imports from real compiled-file paths, so npm trees must stay put.
+    return file.owner.workspace_name != ctx.label.workspace_name or "node_modules" in file.short_path.split("/")
+
 def _is_runtime_file(ctx, file):
     # Other repositories may publish sources as runtime package contents.
-    if file.is_directory or file.owner.workspace_name != ctx.label.workspace_name:
+    if file.is_directory or _is_package_file(ctx, file):
         return True
     return not file.basename.endswith((".ts", ".tsx", ".mts", ".cts", ".map", ".tsbuildinfo"))
 
 def _runtime_directory(ctx, file, directories):
-    if not file.is_directory or file.owner.workspace_name != ctx.label.workspace_name:
+    if not file.is_directory or _is_package_file(ctx, file):
         return file
     if file not in directories:
         output = ctx.actions.declare_directory(ctx.label.name + ".runtime/" + str(len(directories)))
diff --git a/tests/runtime_inputs_test.bzl b/tests/runtime_inputs_test.bzl
index 1717983..de01d29 100644
--- a/tests/runtime_inputs_test.bzl
+++ b/tests/runtime_inputs_test.bzl
@@ -37,7 +37,7 @@ printf 'debug metadata' > "$1/nested/asset.js.map"
                     ctx.label.name + "/root-source-alias": files["source.ts"],
                     ctx.label.name + "/root-directory-alias": tree,
                 },
-            ).merge(ctx.attr._playwright[DefaultInfo].default_runfiles),
+            ).merge(ctx.attr._playwright[DefaultInfo].default_runfiles).merge(ctx.attr._npm[DefaultInfo].default_runfiles),
             data_runfiles = ctx.runfiles(files = [files["data-only.json"]]),
         ),
         OutputGroupInfo(transitive_typecheck = depset([files["semantic-check.txt"]]), assets = depset([tree])),
@@ -49,6 +49,7 @@ _fixture = rule(
         "module": attr.string(),
         "external": attr.label_list(allow_files = True),
         "_playwright": attr.label(default = "//runtime:playwright"),
+        "_npm": attr.label(default = "//:node_modules/typescript"),
     },
     outputs = {"source": "%{name}/source.ts"},
 )
@@ -82,6 +83,10 @@ def _runtime_inputs_test_impl(ctx):
         if file.is_directory:
             asserts.true(env, file in files, "Runtime package must remain unfiltered: " + file.short_path)
             asserts.equals(env, file, aliases.get(file.short_path, file))
+    for file in ctx.attr._npm[DefaultInfo].default_runfiles.files.to_list():
+        if file.is_directory:
+            asserts.true(env, file in files, "Node resolves compiled modules against original npm package trees: " + file.short_path)
+            asserts.equals(env, file, aliases.get(file.short_path, file))
     return analysistest.end(env)
 
 _runtime_inputs_test = analysistest.make(
@@ -91,6 +96,7 @@ _runtime_inputs_test = analysistest.make(
         "explicit_source": attr.bool(),
         "external": attr.label_list(allow_files = True),
         "_playwright": attr.label(default = "//runtime:playwright"),
+        "_npm": attr.label(default = "//:node_modules/typescript"),
     },
 )