diff --git a/Core/MIPS/x86/CompVFPU.cpp b/Core/MIPS/x86/CompVFPU.cpp
index 5ef039b99f..a0698aee82 100644
--- a/Core/MIPS/x86/CompVFPU.cpp
+++ b/Core/MIPS/x86/CompVFPU.cpp
@@ -288,7 +288,13 @@ void Jit::Comp_SVQ(u32 op)
 
 void Jit::Comp_VDot(u32 op) {
 	DISABLE;
+
 	// WARNING: No prefix support!
+	if (js.MayHavePrefix()) {
+		Comp_Generic(op);
+		js.EatPrefix();
+		return;
+	}
 
 	int vd = _VD;
 	int vs = _VS;
@@ -306,7 +312,6 @@ void Jit::Comp_VDot(u32 op) {
 	MOVSS(XMM0, fpr.V(sregs[0]));
 	MULSS(XMM0, fpr.V(tregs[0]));
 
-	float sum = 0.0f;
 	int n = GetNumVectorElements(sz);
 	for (int i = 1; i < n; i++)
 	{
diff --git a/Core/MIPS/x86/Jit.h b/Core/MIPS/x86/Jit.h
index 080375ba7b..b452f9ad97 100644
--- a/Core/MIPS/x86/Jit.h
+++ b/Core/MIPS/x86/Jit.h
@@ -78,6 +78,17 @@ struct JitState
 		prefixTFlag = PREFIX_UNKNOWN;
 		prefixDFlag = PREFIX_UNKNOWN;
 	}
+	bool MayHavePrefix() const {
+		if (!(prefixSFlag & PREFIX_KNOWN) || !(prefixTFlag & PREFIX_KNOWN) || !(prefixDFlag & PREFIX_KNOWN)) {
+			return true;
+		} else if (prefixS != 0xE4 || prefixT != 0xE4 || prefixD != 0) {
+			return true;
+		} else if (writeMask[0] || writeMask[1] || writeMask[2] || writeMask[3]) {
+			return true;
+		}
+
+		return false;
+	}
 	void EatPrefix() {
 		if ((prefixSFlag & PREFIX_KNOWN) == 0 || prefixS != 0xE4) {
 			prefixSFlag = PREFIX_KNOWN_DIRTY;