4 files changed, 23 insertions, 0 deletions
diff --git a/cli/npm/resolution.rs b/cli/npm/resolution.rs
index d56cc87bc..497f40906 100644
--- a/cli/npm/resolution.rs
+++ b/cli/npm/resolution.rs
@@ -77,6 +77,18 @@ impl NpmPackageReference {
     } else {
       Some(parts[name_part_len..].join("/"))
     };
+
+    if let Some(sub_path) = &sub_path {
+      if let Some(at_index) = sub_path.rfind('@') {
+        let (new_sub_path, version) = sub_path.split_at(at_index);
+        let msg = format!(
+          "Invalid package specifier 'npm:{}/{}'. Did you mean to write 'npm:{}{}/{}'?",
+          name, sub_path, name, version, new_sub_path
+        );
+        return Err(generic_error(msg));
+      }
+    }
+
     Ok(NpmPackageReference {
       req: NpmPackageReq { name, version_req },
       sub_path,
diff --git a/cli/tests/integration/npm_tests.rs b/cli/tests/integration/npm_tests.rs
index 32ec12656..de3f81674 100644
--- a/cli/tests/integration/npm_tests.rs
+++ b/cli/tests/integration/npm_tests.rs
@@ -195,6 +195,14 @@ itest!(require_json {
   http_server: true,
 });
 
+itest!(error_version_after_subpath {
+  args: "run --unstable -A --quiet npm/error_version_after_subpath/main.js",
+  output: "npm/error_version_after_subpath/main.out",
+  envs: env_vars(),
+  http_server: true,
+  exit_code: 1,
+});
+
 #[test]
 fn parallel_downloading() {
   let (out, _err) = util::run_and_collect_output_with_args(
diff --git a/cli/tests/testdata/npm/error_version_after_subpath/main.js b/cli/tests/testdata/npm/error_version_after_subpath/main.js
new file mode 100644
index 000000000..77c7a017c
--- /dev/null
+++ b/cli/tests/testdata/npm/error_version_after_subpath/main.js
@@ -0,0 +1 @@
+import "npm:react-dom/server@18.2.0";
diff --git a/cli/tests/testdata/npm/error_version_after_subpath/main.out b/cli/tests/testdata/npm/error_version_after_subpath/main.out
new file mode 100644
index 000000000..0cdd1b6da
--- /dev/null
+++ b/cli/tests/testdata/npm/error_version_after_subpath/main.out
@@ -0,0 +1,2 @@
+error: Invalid package specifier 'npm:react-dom/server@18.2.0'. Did you mean to write 'npm:react-dom@18.2.0/server'?
+    at [WILDCARD]/npm/error_version_after_subpath/main.js:1:8