diff --git a/BUILD.gn b/BUILD.gn
index ee3caab5c0..32d1b527c1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -321,6 +321,11 @@ run_node("bundle") {
 }
 
 source_set("libdeno_nosnapshot") {
+  bundle_outputs = get_target_outputs(":bundle")
+  bundle_location = rebase_path(bundle_outputs[0])
+  bundle_rel_location = rebase_path(bundle_outputs[0], root_build_dir)
+  bundle_map_location = rebase_path(bundle_outputs[1])
+  inputs = bundle_outputs
   sources = [
     "src/from_filesystem.cc",
   ]
@@ -329,9 +334,11 @@ source_set("libdeno_nosnapshot") {
     ":deno_bindings",
   ]
   configs += [ ":deno_config" ]
-  bundle_outputs = get_target_outputs(":bundle")
-  bundle_location = rebase_path(bundle_outputs[0])
-  defines = [ "BUNDLE_LOCATION=\"$bundle_location\"" ]
+  defines = [
+    "BUNDLE_LOCATION=\"$bundle_location\"",
+    "BUNDLE_REL_LOCATION=\"$bundle_rel_location\"",
+    "BUNDLE_MAP_LOCATION=\"$bundle_map_location\"",
+  ]
 }
 
 ts_flatbuffer("msg_ts") {
diff --git a/src/from_filesystem.cc b/src/from_filesystem.cc
index 797659de09..fa50c05151 100644
--- a/src/from_filesystem.cc
+++ b/src/from_filesystem.cc
@@ -1,4 +1,5 @@
 // Copyright 2018 the Deno authors. All rights reserved. MIT license.
+// This file is used to load the bundle at start for deno_ns.
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -17,6 +18,9 @@ Deno* NewFromFileSystem(void* data, deno_recv_cb cb) {
   std::string js_source;
   CHECK(deno::ReadFileToString(BUNDLE_LOCATION, &js_source));
 
+  std::string js_source_map;
+  CHECK(deno::ReadFileToString(BUNDLE_MAP_LOCATION, &js_source_map));
+
   Deno* d = new Deno;
   d->currentArgs = nullptr;
   d->cb = cb;
@@ -32,7 +36,11 @@ Deno* NewFromFileSystem(void* data, deno_recv_cb cb) {
   {
     v8::HandleScope handle_scope(isolate);
     auto context = v8::Context::New(isolate);
-    InitializeContext(isolate, context, BUNDLE_LOCATION, js_source, nullptr);
+    // BUNDLE_LOCATION is absolute so deno_ns can load the bundle independently
+    // of the cwd. However for source maps to work, the bundle location relative
+    // to the build path must be supplied: BUNDLE_REL_LOCATION.
+    InitializeContext(isolate, context, BUNDLE_REL_LOCATION, js_source,
+                      &js_source_map);
     d->context.Reset(d->isolate, context);
   }