diff --git a/src/backend_x64/a64_emit_x64.cpp b/src/backend_x64/a64_emit_x64.cpp
index 4c53f0db..98c25cb8 100644
--- a/src/backend_x64/a64_emit_x64.cpp
+++ b/src/backend_x64/a64_emit_x64.cpp
@@ -261,8 +261,8 @@ void A64EmitX64::EmitA64SetQ(A64EmitContext& ctx, IR::Inst* inst) {
 void A64EmitX64::EmitA64SetSP(A64EmitContext& ctx, IR::Inst* inst) {
     auto args = ctx.reg_alloc.GetArgumentInfo(inst);
     auto addr = qword[r15 + offsetof(A64JitState, sp)];
-    if (args[0].FitsInImmediateU32()) {
-        code->mov(addr, args[0].GetImmediateU32());
+    if (args[0].FitsInImmediateS32()) {
+        code->mov(addr, args[0].GetImmediateS32());
     } else if (args[0].IsInXmm()) {
         Xbyak::Xmm to_store = ctx.reg_alloc.UseXmm(args[0]);
         code->movq(addr, to_store);
@@ -275,8 +275,8 @@ void A64EmitX64::EmitA64SetSP(A64EmitContext& ctx, IR::Inst* inst) {
 void A64EmitX64::EmitA64SetPC(A64EmitContext& ctx, IR::Inst* inst) {
     auto args = ctx.reg_alloc.GetArgumentInfo(inst);
     auto addr = qword[r15 + offsetof(A64JitState, pc)];
-    if (args[0].FitsInImmediateU32()) {
-        code->mov(addr, args[0].GetImmediateU32());
+    if (args[0].FitsInImmediateS32()) {
+        code->mov(addr, args[0].GetImmediateS32());
     } else if (args[0].IsInXmm()) {
         Xbyak::Xmm to_store = ctx.reg_alloc.UseXmm(args[0]);
         code->movq(addr, to_store);