diff --git a/include/sirit/sirit.h b/include/sirit/sirit.h
index 3387ac0..3456110 100644
--- a/include/sirit/sirit.h
+++ b/include/sirit/sirit.h
@@ -219,6 +219,11 @@ class Module {
                        spv::Decoration decoration,
                        const std::vector<Literal>& literals = {});
 
+    // Misc
+
+    /// Make an intermediate object whose value is undefined.
+    Ref Undef(Ref result_type);
+
   private:
     Ref AddCode(Op* op);
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index db94e83..08fa9be 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -20,6 +20,7 @@ add_library(sirit
     insts/debug.cpp
     insts/memory.cpp
     insts/annotation.cpp
+    insts/misc.cpp
 )
 target_include_directories(sirit
                            PUBLIC ../include
diff --git a/src/insts/misc.cpp b/src/insts/misc.cpp
new file mode 100644
index 0000000..e21d00e
--- /dev/null
+++ b/src/insts/misc.cpp
@@ -0,0 +1,17 @@
+/* This file is part of the sirit project.
+ * Copyright (c) 2018 ReinUsesLisp
+ * This software may be used and distributed according to the terms of the GNU
+ * Lesser General Public License version 2.1 or any later version.
+ */
+
+#include "insts.h"
+#include "sirit/sirit.h"
+#include <cassert>
+
+namespace Sirit {
+
+Ref Module::Undef(Ref result_type) {
+    return AddCode(new Op(spv::Op::OpUndef, bound++, result_type));
+}
+
+} // namespace Sirit