diff --git a/common/util/Util/FFI.hs b/common/util/Util/FFI.hs
index 5ff71607..0626fd62 100644
--- a/common/util/Util/FFI.hs
+++ b/common/util/Util/FFI.hs
@@ -18,9 +18,6 @@ import System.IO.Unsafe (unsafePerformIO)
 import Control.Exception
 import Control.Monad
 
-foreign import ccall unsafe "&hs_ffi_free_error" hs_ffi_free_error
-  :: FunPtr (CString -> IO ())
-
 newtype FFIError = FFIError (ForeignPtr CChar)
 
 ffiErrorMessage :: FFIError -> String
@@ -39,7 +36,13 @@ call :: IO CString -> IO ()
 call f = do
   p <- f
   when (p /= nullPtr) $ do
-    fp <- newForeignPtr hs_ffi_free_error p
+    fp <- do
+      b <- peek p
+      -- A '\1' prefix indicates that we shouldn't free the string (e.g.,
+      -- because it's static) - cf. ffi::wrap.
+      if b /= toEnum 1
+        then newForeignPtr finalizerFree p
+        else newForeignPtr_ (p `plusPtr` 1)
     throwIO $ FFIError fp
 
 infixr 5 :>
diff --git a/common/util/cpp/ffi.cpp b/common/util/cpp/ffi.cpp
deleted file mode 100644
index 646df50a..00000000
--- a/common/util/cpp/ffi.cpp
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#include "cpp/ffi.h"
-#include "cpp/wrap.h"
-
-namespace facebook {
-namespace hs {
-namespace ffi {
-
-const char* outOfMemory = "out of memory";
-const char* unknownError = "unknown error";
-
-} // namespace ffi
-} // namespace hs
-} // namespace facebook
-
-extern "C" {
-
-void hs_ffi_free_error(const char* err) {
-  if (err != facebook::hs::ffi::outOfMemory &&
-      err != facebook::hs::ffi::unknownError) {
-    std::free(const_cast<char*>(err));
-  }
-}
-}
diff --git a/common/util/cpp/ffi.h b/common/util/cpp/ffi.h
deleted file mode 100644
index d244e172..00000000
--- a/common/util/cpp/ffi.h
+++ /dev/null
@@ -1,19 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and affiliates.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree.
- */
-
-#pragma once
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void hs_ffi_free_error(const char* error);
-
-#ifdef __cplusplus
-}
-#endif
diff --git a/common/util/cpp/wrap.h b/common/util/cpp/wrap.h
index bed22457..d1264721 100644
--- a/common/util/cpp/wrap.h
+++ b/common/util/cpp/wrap.h
@@ -15,11 +15,15 @@ namespace facebook {
 namespace hs {
 namespace ffi {
 
-extern const char* outOfMemory;
-extern const char* unknownError;
-
 template <typename F>
 const char* wrap(F&& f) noexcept {
+  // The '\1' prefix instructs the marshaller in FFI.hs to not free those
+  // strings. The prefix itself will be stripped out. This is only really
+  // necessary specifically for the outOfMemory message where we might not be
+  // able to allocate a new message string - although arguably, we might just
+  // want to abort in such a case.
+  static const char *outOfMemory = "\1out of memory";
+  static const char *unknownError = "\1unknown error";
   try {
     f();
     return nullptr;
diff --git a/common/util/fb-util.cabal b/common/util/fb-util.cabal
index 48544269..6ffd9a1a 100644
--- a/common/util/fb-util.cabal
+++ b/common/util/fb-util.cabal
@@ -156,7 +156,6 @@ library
 
     cxx-sources:
         cpp/cdynamic.cpp
-        cpp/ffi.cpp
         cpp/logging.cpp
         cpp/HsStruct.cpp
         cpp/IOBuf.cpp
@@ -171,7 +170,6 @@ library
         cpp/HsStdVariant.h
         cpp/HsStruct.h
         cpp/HsStructDefines.h
-        cpp/ffi.h
         cpp/memory.h
         cpp/wrap.h
         Util/AsanAlloc.h