diff --git a/Core/HLE/ReplaceTables.cpp b/Core/HLE/ReplaceTables.cpp
index 30afa6e26b..f71b8b945c 100644
--- a/Core/HLE/ReplaceTables.cpp
+++ b/Core/HLE/ReplaceTables.cpp
@@ -1590,7 +1590,10 @@ std::vector<int> GetReplacementFuncIndexes(u64 hash, int funcSize) {
 	return emptyResult;
 }
 
-const ReplacementTableEntry *GetReplacementFunc(int i) {
+const ReplacementTableEntry *GetReplacementFunc(size_t i) {
+	if (i >= ARRAY_SIZE(entries)) {
+		return nullptr;
+	}
 	return &entries[i];
 }
 
diff --git a/Core/HLE/ReplaceTables.h b/Core/HLE/ReplaceTables.h
index 94ee26d69e..980f506b6a 100644
--- a/Core/HLE/ReplaceTables.h
+++ b/Core/HLE/ReplaceTables.h
@@ -64,7 +64,7 @@ void Replacement_Shutdown();
 
 int GetNumReplacementFuncs();
 std::vector<int> GetReplacementFuncIndexes(u64 hash, int funcSize);
-const ReplacementTableEntry *GetReplacementFunc(int index);
+const ReplacementTableEntry *GetReplacementFunc(size_t index);
 
 void WriteReplaceInstructions(u32 address, u64 hash, int size);
 void RestoreReplacedInstruction(u32 address);
diff --git a/Core/MIPS/ARM64/Arm64Jit.cpp b/Core/MIPS/ARM64/Arm64Jit.cpp
index d1f1062f1e..c412a2a34b 100644
--- a/Core/MIPS/ARM64/Arm64Jit.cpp
+++ b/Core/MIPS/ARM64/Arm64Jit.cpp
@@ -563,6 +563,7 @@ void Arm64Jit::Comp_ReplacementFunc(MIPSOpcode op)
 	const ReplacementTableEntry *entry = GetReplacementFunc(index);
 	if (!entry) {
 		ERROR_LOG(HLE, "Invalid replacement op %08x", op.encoding);
+		// TODO: What should we do here? We're way off in the weeds probably.
 		return;
 	}