diff --git a/src/codegen/x86_64/CodeGen.zig b/src/codegen/x86_64/CodeGen.zig
index c3b548b58a7ae0624b7bbea3c25fb93794b2ae9d..ef8a83e3f1cddce79fe3e9bce2e18817d6826ac6 100644
--- a/src/codegen/x86_64/CodeGen.zig
+++ b/src/codegen/x86_64/CodeGen.zig
@@ -180695,6 +180695,7 @@ fn airMemset(self: *CodeGen, inst: Air.Inst.Index, safety: bool) !void {
                 const len_lock = self.register_manager.lockRegAssumeUnused(len_reg);
                 defer self.register_manager.unlockReg(len_lock);
 
+                try self.spillEflagsIfOccupied();
                 try self.genSetReg(len_reg, .usize, len, .{});
                 try self.asmRegisterRegister(.{ ._, .@"test" }, len_reg, len_reg);