diff --git a/src/frontend/A64/translate/impl/load_store_register_pair.cpp b/src/frontend/A64/translate/impl/load_store_register_pair.cpp
index ba990899..6283aa0f 100644
--- a/src/frontend/A64/translate/impl/load_store_register_pair.cpp
+++ b/src/frontend/A64/translate/impl/load_store_register_pair.cpp
@@ -61,6 +61,8 @@ bool TranslatorVisitor::STP_LDP_gen(Imm<2> opc, bool not_postindex, bool wback,
         }
         break;
     }
+    case MemOp::PREFETCH:
+        UNREACHABLE();
     }
 
     if (wback) {