diff --git a/ext/ffi/jit_trampoline.rs b/ext/ffi/jit_trampoline.rs
index 12c9b2a7d8..6a3efa8764 100644
--- a/ext/ffi/jit_trampoline.rs
+++ b/ext/ffi/jit_trampoline.rs
@@ -56,7 +56,7 @@ fn native_to_c(ty: &NativeType) -> &'static str {
 }
 
 pub(crate) fn codegen(sym: &crate::Symbol) -> String {
-  let mut c = String::from("#include <stdint.h>\n");
+  let mut c = String::from(include_str!("prelude.h"));
   let ret = native_to_c(&sym.result_type);
 
   // extern <return_type> func(
@@ -130,75 +130,72 @@ mod tests {
     super::codegen(&sym)
   }
 
+  const PRELUDE: &str = include_str!("prelude.h");
+  fn assert_codegen(expected: String, actual: &str) {
+    assert_eq!(expected, format!("{PRELUDE}\n{}", actual))
+  }
+
   #[test]
   fn test_gen_trampoline() {
-    assert_eq!(
+    assert_codegen(
       codegen(vec![], NativeType::Void),
-      "#include <stdint.h>\n\n\
-      extern void func();\n\n\
+      "extern void func();\n\n\
       void func_trampoline(void* recv) {\
         \n  return func();\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::U32, NativeType::U32], NativeType::U32),
-      "#include <stdint.h>\n\n\
-      extern uint32_t func(uint32_t p0, uint32_t p1);\n\n\
+      "extern uint32_t func(uint32_t p0, uint32_t p1);\n\n\
       uint32_t func_trampoline(void* recv, uint32_t p0, uint32_t p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::I32, NativeType::I32], NativeType::I32),
-      "#include <stdint.h>\n\n\
-      extern int32_t func(int32_t p0, int32_t p1);\n\n\
+      "extern int32_t func(int32_t p0, int32_t p1);\n\n\
       int32_t func_trampoline(void* recv, int32_t p0, int32_t p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::F32, NativeType::F32], NativeType::F32),
-      "#include <stdint.h>\n\n\
-      extern float func(float p0, float p1);\n\n\
+      "extern float func(float p0, float p1);\n\n\
       float func_trampoline(void* recv, float p0, float p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::F64, NativeType::F64], NativeType::F64),
-      "#include <stdint.h>\n\n\
-      extern double func(double p0, double p1);\n\n\
+      "extern double func(double p0, double p1);\n\n\
       double func_trampoline(void* recv, double p0, double p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
   }
 
   #[test]
   fn test_gen_trampoline_implicit_cast() {
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::I8, NativeType::U8], NativeType::I8),
-      "#include <stdint.h>\n\n\
-      extern int8_t func(int8_t p0, uint8_t p1);\n\n\
+      "extern int8_t func(int8_t p0, uint8_t p1);\n\n\
       int8_t func_trampoline(void* recv, int32_t p0, uint32_t p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::ISize, NativeType::U64], NativeType::Void),
-      "#include <stdint.h>\n\n\
-      extern void func(intptr_t p0, uint64_t p1);\n\n\
+      "extern void func(intptr_t p0, uint64_t p1);\n\n\
       void func_trampoline(void* recv, intptr_t p0, uint64_t p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
-    assert_eq!(
+    assert_codegen(
       codegen(vec![NativeType::USize, NativeType::USize], NativeType::U32),
-      "#include <stdint.h>\n\n\
-      extern uint32_t func(uintptr_t p0, uintptr_t p1);\n\n\
+      "extern uint32_t func(uintptr_t p0, uintptr_t p1);\n\n\
       uint32_t func_trampoline(void* recv, uintptr_t p0, uintptr_t p1) {\
         \n  return func(p0, p1);\n\
-      }\n\n"
+      }\n\n",
     );
   }
 }
diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index 6d03159644..a03bb41d62 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -10,13 +10,11 @@ use deno_core::futures::channel::mpsc;
 use deno_core::futures::Future;
 use deno_core::include_js_files;
 use deno_core::op;
-use deno_core::v8::fast_api;
-use std::sync::mpsc::sync_channel;
-
 use deno_core::serde_json::json;
 use deno_core::serde_json::Value;
 use deno_core::serde_v8;
 use deno_core::v8;
+use deno_core::v8::fast_api;
 use deno_core::Extension;
 use deno_core::OpState;
 use deno_core::Resource;
@@ -33,17 +31,30 @@ use std::cell::RefCell;
 use std::collections::HashMap;
 use std::ffi::c_void;
 use std::ffi::CStr;
+use std::mem::size_of;
 use std::os::raw::c_char;
+use std::os::raw::c_short;
 use std::path::Path;
 use std::path::PathBuf;
 use std::ptr;
 use std::rc::Rc;
+use std::sync::mpsc::sync_channel;
 
 #[cfg(not(target_os = "windows"))]
 mod jit_trampoline;
 #[cfg(not(target_os = "windows"))]
 mod tcc;
 
+#[cfg(not(target_pointer_width = "64"))]
+compile_error!("platform not supported");
+
+// Assert assumptions made in `prelude.h`
+const _: () = {
+  assert!(size_of::<c_char>() == 1);
+  assert!(size_of::<c_short>() == 2);
+  assert!(size_of::<*const ()>() == 8);
+};
+
 thread_local! {
   static LOCAL_ISOLATE_POINTER: RefCell<*const v8::Isolate> = RefCell::new(ptr::null());
 }
diff --git a/ext/ffi/prelude.h b/ext/ffi/prelude.h
new file mode 100644
index 0000000000..ed3d14e1a0
--- /dev/null
+++ b/ext/ffi/prelude.h
@@ -0,0 +1,19 @@
+// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
+
+/* Exact integral types.  */
+
+/* Signed.  */
+typedef signed char int8_t;
+typedef short int int16_t;
+typedef int int32_t;
+typedef long int int64_t;
+
+/* Unsigned.  */
+typedef unsigned char uint8_t;
+typedef unsigned short int uint16_t;
+typedef unsigned int uint32_t;
+typedef unsigned long int uint64_t;
+
+/* Types for `void *' pointers.  */
+typedef long int intptr_t;
+typedef unsigned long int uintptr_t;