diff --git a/lib/compiler/std-docs.zig b/lib/compiler/std-docs.zig
index 93a04a28e5..d86be67702 100644
--- a/lib/compiler/std-docs.zig
+++ b/lib/compiler/std-docs.zig
@@ -177,6 +177,26 @@ fn serveSourcesTar(request: *std.http.Server.Request, context: *Context) !void {
         try w.writeFile(file);
         try w.writeByteNTimes(0, padding);
     }
+
+    {
+        // Since this command is JIT compiled, the builtin module available in
+        // this source file corresponds to the user's host system.
+        const builtin_zig = @embedFile("builtin");
+
+        var file_header = std.tar.output.Header.init();
+        file_header.typeflag = .regular;
+        try file_header.setPath("builtin", "builtin.zig");
+        try file_header.setSize(builtin_zig.len);
+        try file_header.updateChecksum();
+        try w.writeAll(std.mem.asBytes(&file_header));
+        try w.writeAll(builtin_zig);
+        const padding = p: {
+            const remainder = builtin_zig.len % 512;
+            break :p if (remainder > 0) 512 - remainder else 0;
+        };
+        try w.writeByteNTimes(0, padding);
+    }
+
     // intentionally omitting the pointless trailer
     //try w.writeByteNTimes(0, 512 * 2);
     try response.end();
diff --git a/src/Compilation.zig b/src/Compilation.zig
index 5bbca51ede..460a1e5d9e 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -3693,6 +3693,9 @@ fn workerDocsCopy(comp: *Compilation, wg: *WaitGroup) void {
 }
 
 fn docsCopyFallible(comp: *Compilation) anyerror!void {
+    const zcu = comp.module orelse
+        return comp.lockAndSetMiscFailure(.docs_copy, "no Zig code to document", .{});
+
     const emit = comp.docs_emit.?;
     var out_dir = emit.directory.handle.makeOpenPath(emit.sub_path, .{}) catch |err| {
         return comp.lockAndSetMiscFailure(
@@ -3723,7 +3726,25 @@ fn docsCopyFallible(comp: *Compilation) anyerror!void {
     };
     defer tar_file.close();
 
-    const root = comp.root_mod.root;
+    var seen_table: std.AutoArrayHashMapUnmanaged(*Package.Module, void) = .{};
+    defer seen_table.deinit(comp.gpa);
+
+    try seen_table.put(comp.gpa, zcu.main_mod, {});
+    try seen_table.put(comp.gpa, zcu.std_mod, {});
+
+    var i: usize = 0;
+    while (i < seen_table.count()) : (i += 1) {
+        const mod = seen_table.keys()[i];
+        try comp.docsCopyModule(mod, tar_file);
+
+        const deps = mod.deps.values();
+        try seen_table.ensureUnusedCapacity(comp.gpa, deps.len);
+        for (deps) |dep| seen_table.putAssumeCapacity(dep, {});
+    }
+}
+
+fn docsCopyModule(comp: *Compilation, module: *Package.Module, tar_file: std.fs.File) !void {
+    const root = module.root;
     const sub_path = if (root.sub_path.len == 0) "." else root.sub_path;
     var mod_dir = root.root_dir.handle.openDir(sub_path, .{ .iterate = true }) catch |err| {
         return comp.lockAndSetMiscFailure(.docs_copy, "unable to open directory '{}': {s}", .{
@@ -3762,7 +3783,7 @@ fn docsCopyFallible(comp: *Compilation) anyerror!void {
 
         var file_header = std.tar.output.Header.init();
         file_header.typeflag = .regular;
-        try file_header.setPath(comp.root_name, entry.path);
+        try file_header.setPath(module.fully_qualified_name, entry.path);
         try file_header.setSize(stat.size);
         try file_header.updateChecksum();