diff --git a/js/src/jit/riscv64/LIR-riscv64.h b/js/src/jit/riscv64/LIR-riscv64.h
index eb87e7448dfc5..bdd68a54ef9f5 100644
--- a/js/src/jit/riscv64/LIR-riscv64.h
+++ b/js/src/jit/riscv64/LIR-riscv64.h
@@ -1629,6 +1629,22 @@ getInt64Operand
 ;
 }
 const
+LAllocation
+*
+memoryBase
+(
+)
+{
+return
+getOperand
+(
+1
++
+INT64_PIECES
+)
+;
+}
+const
 MWasmAtomicExchangeHeap
 *
 mir
diff --git a/js/src/wasm/WasmBCMemory.cpp b/js/src/wasm/WasmBCMemory.cpp
index a2c2d14522cda..979d5191e868b 100644
--- a/js/src/wasm/WasmBCMemory.cpp
+++ b/js/src/wasm/WasmBCMemory.cpp
@@ -5000,12 +5000,6 @@ temp
 elif
 defined
 (
-JS_CODEGEN_MIPS64
-)
-|
-|
-defined
-(
 JS_CODEGEN_RISCV64
 )
 /
@@ -5063,6 +5057,7 @@ executeLoad
 access
 check
 instance
+memoryBase
 RegI32
 (
 ptr
@@ -9824,7 +9819,7 @@ const
 MemoryAccessDesc
 &
 access
-BaseIndex
+Address
 srcAddr
 AtomicOp
 op
@@ -11094,7 +11089,7 @@ const
 MemoryAccessDesc
 &
 access
-BaseIndex
+Address
 srcAddr
 AtomicOp
 op
@@ -12547,7 +12542,7 @@ const
 MemoryAccessDesc
 &
 access
-BaseIndex
+Address
 srcAddr
 RegI32
 rv
@@ -15080,7 +15075,7 @@ const
 MemoryAccessDesc
 &
 access
-BaseIndex
+Address
 srcAddr
 RegI32
 rexpect
@@ -16783,7 +16778,7 @@ const
 MemoryAccessDesc
 &
 access
-BaseIndex
+Address
 srcAddr
 RegI64
 rexpect