diff --git a/tinygrad/renderer/isa/x86.py b/tinygrad/renderer/isa/x86.py
index f4ac03286e..8bfec78904 100644
--- a/tinygrad/renderer/isa/x86.py
+++ b/tinygrad/renderer/isa/x86.py
@@ -224,6 +224,8 @@ XMM = tuple(Register(f"xmm{i}", i) for i in range(16))
 # gprs you can write to
 WGPR = tuple(r for r in GPR if r != RSP)
 
+CALLEE_SAVED = (RBX, RSP, RBP, GPR[12], GPR[13], GPR[14], GPR[15]) + ((RSI, RDI) + XMM[6:16] if sys.platform == "win32" else ())
+
 reg_strs = {"rax": {4:"eax", 2:"ax", 1:"al"}, "rcx": {4:"ecx", 2:"cx", 1:"cl"}, "rdx": {4:"edx", 2:"dx", 1:"dl"}, "rbx": {4:"ebx", 2:"bx", 1:"bl"},
         "rsp": {4:"esp", 2:"sp", 1:"spl"}, "rbp": {4:"ebp", 2:"bp", 1:"bpl"}, "rsi": {4:"esi", 2:"si", 1:"sil"}, "rdi": {4:"edi", 2:"di", 1:"dil"},
         **{f"r{i}": {4:f"r{i}d", 2:f"r{i}w", 1:f"r{i}b"} for i in range(8, 16)}, **{f"xmm{i}": {64:f"zmm{i}", 32:f"ymm{i}"} for i in range(16)}}
@@ -366,7 +368,8 @@ isel_matcher = PatternMatcher([
   # **** Op -> X86Op ****
   # add callee saved registers to the RET, these will be scheduled at the top of the kernel and will be saved/restored if they are used in regalloc
   # so regalloc builds the prologue/epilogue naturally
-  (UPat(Ops.SINK, name="x"), lambda x: x.ins(X86Ops.RET, src=x.src + tuple(def_reg(dtypes.uint64, r) for r in [RSP, RBP]))),
+  (UPat(Ops.SINK, name="x"), lambda x:
+   x.ins(X86Ops.RET, src=x.src + tuple(def_reg(dtypes.uint64 if r in GPR else dtypes.float64.vec(2), r) for r in CALLEE_SAVED))),
   # function abi constraints
   (UPat((Ops.PARAM, Ops.DEFINE_VAR, Ops.SPECIAL), name="x"), abi),
   # these are treated the same for now