diff --git a/src/bundler.zig b/src/bundler.zig
index d88ac80f50..cbfaea2c12 100644
--- a/src/bundler.zig
+++ b/src/bundler.zig
@@ -103,6 +103,12 @@ pub const PluginRunner = struct {
 
     pub fn extractNamespace(specifier: string) string {
         const colon = strings.indexOfChar(specifier, ':') orelse return "";
+        if (Environment.isWindows and
+            colon == 1 and
+            specifier.len > 3 and
+            bun.path.isSepAny(specifier[2]) and
+            ((specifier[0] > 'a' and specifier[0] < 'z') or (specifier[0] > 'A' and specifier[0] < 'Z')))
+            return "";
         return specifier[0..colon];
     }
 
diff --git a/src/js/builtins/BundlerPlugin.ts b/src/js/builtins/BundlerPlugin.ts
index d2c88b667d..db78902f2d 100644
--- a/src/js/builtins/BundlerPlugin.ts
+++ b/src/js/builtins/BundlerPlugin.ts
@@ -253,7 +253,9 @@ export function runOnResolvePlugins(this: BundlerPlugin, specifier, inputNamespa
                 throw new TypeError('onResolve plugin "path" must be absolute when the namespace is "file"');
               }
             } else {
-              // TODO: Windows
+              if (require("node:path").isAbsolute(path) === false || path.includes("..")) {
+                throw new TypeError('onResolve plugin "path" must be absolute when the namespace is "file"');
+              }
             }
           }
           if (userNamespace === "dataurl") {
diff --git a/src/string_immutable.zig b/src/string_immutable.zig
index 733f6a5552..3b55d41beb 100644
--- a/src/string_immutable.zig
+++ b/src/string_immutable.zig
@@ -5841,3 +5841,17 @@ pub const QuoteEscapeFormat = struct {
         try writer.writeAll(self.data[i..]);
     }
 };
+
+/// Generic. Works on []const u8, []const u16, etc
+pub inline fn indexOfScalar(input: anytype, scalar: std.meta.Child(@TypeOf(input))) ?usize {
+    if (comptime std.meta.Child(@TypeOf(input)) == u8) {
+        return strings.indexOfCharUsize(input, scalar);
+    } else {
+        return std.mem.indexOfScalar(std.meta.Child(@TypeOf(input)), input, scalar);
+    }
+}
+
+/// Generic. Works on []const u8, []const u16, etc
+pub fn containsScalar(input: anytype, item: std.meta.Child(@TypeOf(input))) bool {
+    return indexOfScalar(input, item) != null;
+}
diff --git a/test/js/bun/plugin/muh.ts b/test/js/bun/plugin/muh.ts
new file mode 100644
index 0000000000..d5fbbcd864
--- /dev/null
+++ b/test/js/bun/plugin/muh.ts
@@ -0,0 +1,24 @@
+import { plugin } from "bun";
+
+await plugin({
+  name: "svelte loader",
+  async setup(builder) {
+    var { compile } = await import("svelte/compiler");
+    var { readFileSync } = await import("fs");
+    await 2;
+    console.log(1);
+    builder.onLoad({ filter: /\.svelte$/ }, ({ path }) => {
+      console.log(2);
+      return {
+        contents: compile(readFileSync(path, "utf8"), {
+          filename: path,
+          generate: "ssr",
+        }).js.code,
+        loader: "js",
+      };
+    });
+    await 1;
+  },
+});
+
+console.log(require("./hello.svelte"));
diff --git a/test/js/bun/plugin/plugins.test.ts b/test/js/bun/plugin/plugins.test.ts
index 9425afed8b..e82c357a28 100644
--- a/test/js/bun/plugin/plugins.test.ts
+++ b/test/js/bun/plugin/plugins.test.ts
@@ -320,7 +320,7 @@ describe("dynamic import", () => {
 describe("import statement", () => {
   it("SSRs `<h1>Hello world!</h1>` with Svelte", async () => {
     laterCode = `
-import Hello from "${resolve(import.meta.dir, "hello2.svelte")}";
+import Hello from ${JSON.stringify(resolve(import.meta.dir, "hello2.svelte"))};
 export default Hello;
 `;
     const { default: SvelteApp } = await import("delay:hello2.svelte");