diff --git a/lib/std/child_process.zig b/lib/std/child_process.zig
index 02d8693e2c..156f9f2924 100644
--- a/lib/std/child_process.zig
+++ b/lib/std/child_process.zig
@@ -636,7 +636,7 @@ pub const ChildProcess = struct {
             retry: while (it.next()) |search_path| {
                 var ext_it = mem.tokenize(PATHEXT, ";");
                 while (ext_it.next()) |app_ext| {
-                    const app_basename = try mem.concat(self.allocator, u8, &[_][]const u8{ app_name[0 .. app_name.len - 1], app_ext });
+                    const app_basename = try mem.concat(self.allocator, u8, &[_][]const u8{ app_name, app_ext });
                     defer self.allocator.free(app_basename);
 
                     const joined_path = try fs.path.join(self.allocator, &[_][]const u8{ search_path, app_basename });