GeezerVison

diff --git a/Tools/jit/_targets.py b/Tools/jit/_targets.py
index 37b3e596bd..fd82eda697 100644
--- a/Tools/jit/_targets.py
+++ b/Tools/jit/_targets.py
@@ -37,6 +37,7 @@
 @dataclasses.dataclass
 class _Target(typing.Generic[_S, _R]):
     triple: str
+    condition: str
     _: dataclasses.KW_ONLY
     alignment: int = 1
     prefix: str = ""
@@ -108,7 +109,6 @@ async def _compile(
         o = tempdir / f"{opname}.o"
         args = [
             f"--target={self.triple}",
-            "-isysroot", "/Users/ronald/Applications/Xcode-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk",
             "-DPy_BUILD_CORE",
             "-D_DEBUG" if self.debug else "-DNDEBUG",
             f"-D_JIT_OPCODE={opname}",
@@ -383,15 +383,21 @@ def _handle_relocation(
 def get_target(host: str) -> _COFF | _ELF | _MachO:
     """Build a _Target for the given host "triple" and options."""
     if re.fullmatch(r"aarch64-apple-darwin.*", host):
-        return _MachO(host, alignment=8, prefix="_")
+        condition = "defined(__aarch64__) && defined(__APPLE__)"
+        return _MachO(host, condition, alignment=8, prefix="_")
     if re.fullmatch(r"aarch64-.*-linux-gnu", host):
-        return _ELF(host, alignment=8)
+        condition = "defined(__aarch64__) && defined(__linux__)"
+        return _ELF(host, condition, alignment=8)
     if re.fullmatch(r"i686-pc-windows-msvc", host):
-        return _COFF(host, prefix="_")
+        condition = "defined(_M_IX86)"
+        return _COFF(host, condition, prefix="_")
     if re.fullmatch(r"x86_64-apple-darwin.*", host):
-        return _MachO(host, prefix="_")
+        condition = "defined(__x86_64__) && defined(__APPLE__)"
+        return _MachO(host, condition, prefix="_")
     if re.fullmatch(r"x86_64-pc-windows-msvc", host):
-        return _COFF(host)
+        condition = "defined(_M_X64)"
+        return _COFF(host, condition)
     if re.fullmatch(r"x86_64-.*-linux-gnu", host):
-        return _ELF(host)
+        condition = "defined(__x86_64__) && defined(__linux__)"
+        return _ELF(host, condition)
     raise ValueError(host)
diff --git a/Tools/jit/build.py b/Tools/jit/build.py
index 800d8e31b0..7872004a90 100644
--- a/Tools/jit/build.py
+++ b/Tools/jit/build.py
@@ -42,8 +42,7 @@
 
         with open("jit_stencils.h", "w") as fp:
             for idx, target in enumerate(args.target):
-                cpu, _, _ = target.triple.partition("-")
-                fp.write(f"#{'if' if idx == 0 else 'elif'} defined(__{cpu}__)\n")
+                fp.write(f"#{'if' if idx == 0 else 'elif'} {target.condition}\n")
                 fp.write(f'#   include "jit_stencils-{target.triple}.h"\n')
 
             fp.write("#else\n")