diff --git a/Core/MIPS/IR/IRPassSimplify.cpp b/Core/MIPS/IR/IRPassSimplify.cpp
index a6a939cd46..3285ff194d 100644
--- a/Core/MIPS/IR/IRPassSimplify.cpp
+++ b/Core/MIPS/IR/IRPassSimplify.cpp
@@ -126,6 +126,9 @@ bool PropagateConstants(const IRWriter &in, IRWriter &out) {
 		case IROp::SetConst:
 			gpr.SetImm(inst.dest, constants[inst.src1]);
 			break;
+		case IROp::SetConstF:
+		case IROp::SetConstV:
+			goto doDefault;
 
 		case IROp::Sub:
 		case IROp::Slt:
@@ -381,6 +384,22 @@ bool PropagateConstants(const IRWriter &in, IRWriter &out) {
 			}
 			break;
 
+		case IROp::ZeroFpCond:
+		case IROp::FCmpUnordered:
+		case IROp::FCmpEqual:
+		case IROp::FCmpEqualUnordered:
+		case IROp::FCmpLessOrdered:
+		case IROp::FCmpLessUnordered:
+		case IROp::FCmpLessEqualOrdered:
+		case IROp::FCmpLessEqualUnordered:
+			gpr.MapDirty(IRREG_FPCOND);
+			goto doDefault;
+
+		case IROp::RestoreRoundingMode:
+		case IROp::ApplyRoundingMode:
+		case IROp::UpdateRoundingMode:
+			goto doDefault;
+
 		case IROp::VfpuCtrlToReg:
 			gpr.MapDirtyIn(inst.dest, IRREG_VPFU_CTRL_BASE + inst.src1);
 			goto doDefault;