diff --git a/src/cmd/compile/internal/ssa/gen/Wasm.rules b/src/cmd/compile/internal/ssa/gen/Wasm.rules
index cede359c538..7994fb7f5ba 100644
--- a/src/cmd/compile/internal/ssa/gen/Wasm.rules
+++ b/src/cmd/compile/internal/ssa/gen/Wasm.rules
@@ -377,15 +377,10 @@
 (I64Add x (I64Const [y])) -> (I64AddConst [y] x)
 (I64Eqz (I64Eqz (I64Eqz x))) -> (I64Eqz x)
 
-(I64Store8 [off] (I64AddConst [off2] ptr) val mem) && off+off2 >= 0 -> (I64Store8 [off+off2] ptr val mem)
-(I64Store16 [off] (I64AddConst [off2] ptr) val mem) && off+off2 >= 0 -> (I64Store16 [off+off2] ptr val mem)
-(I64Store32 [off] (I64AddConst [off2] ptr) val mem) && off+off2 >= 0 -> (I64Store32 [off+off2] ptr val mem)
-(I64Store [off] (I64AddConst [off2] ptr) val mem) && off+off2 >= 0 -> (I64Store [off+off2] ptr val mem)
+((I64Load|I64Load32U|I64Load32S|I64Load16U|I64Load16S|I64Load8U|I64Load8S) [off] (I64AddConst [off2] ptr) mem)
+	&& isU32Bit(off+off2) ->
+	((I64Load|I64Load32U|I64Load32S|I64Load16U|I64Load16S|I64Load8U|I64Load8S) [off+off2] ptr mem)
 
-(I64Load8U [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load8U [off+off2] ptr mem)
-(I64Load8S [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load8S [off+off2] ptr mem)
-(I64Load16U [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load16U [off+off2] ptr mem)
-(I64Load16S [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load16S [off+off2] ptr mem)
-(I64Load32U [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load32U [off+off2] ptr mem)
-(I64Load32S [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load32S [off+off2] ptr mem)
-(I64Load [off] (I64AddConst [off2] ptr) mem) && off+off2 >= 0 -> (I64Load [off+off2] ptr mem)
+((I64Store|I64Store32|I64Store16|I64Store8) [off] (I64AddConst [off2] ptr) val mem)
+	&& isU32Bit(off+off2) ->
+	((I64Store|I64Store32|I64Store16|I64Store8) [off+off2] ptr val mem)
diff --git a/src/cmd/compile/internal/ssa/rewriteWasm.go b/src/cmd/compile/internal/ssa/rewriteWasm.go
index f488a935224..22555610514 100644
--- a/src/cmd/compile/internal/ssa/rewriteWasm.go
+++ b/src/cmd/compile/internal/ssa/rewriteWasm.go
@@ -5256,7 +5256,7 @@ func rewriteValueWasm_OpWasmI64Eqz_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load_0(v *Value) bool {
 	// match: (I64Load [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5268,7 +5268,7 @@ func rewriteValueWasm_OpWasmI64Load_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load)
@@ -5281,7 +5281,7 @@ func rewriteValueWasm_OpWasmI64Load_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load16S_0(v *Value) bool {
 	// match: (I64Load16S [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load16S [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5293,7 +5293,7 @@ func rewriteValueWasm_OpWasmI64Load16S_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load16S)
@@ -5306,7 +5306,7 @@ func rewriteValueWasm_OpWasmI64Load16S_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load16U_0(v *Value) bool {
 	// match: (I64Load16U [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load16U [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5318,7 +5318,7 @@ func rewriteValueWasm_OpWasmI64Load16U_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load16U)
@@ -5331,7 +5331,7 @@ func rewriteValueWasm_OpWasmI64Load16U_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load32S_0(v *Value) bool {
 	// match: (I64Load32S [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load32S [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5343,7 +5343,7 @@ func rewriteValueWasm_OpWasmI64Load32S_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load32S)
@@ -5356,7 +5356,7 @@ func rewriteValueWasm_OpWasmI64Load32S_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load32U_0(v *Value) bool {
 	// match: (I64Load32U [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load32U [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5368,7 +5368,7 @@ func rewriteValueWasm_OpWasmI64Load32U_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load32U)
@@ -5381,7 +5381,7 @@ func rewriteValueWasm_OpWasmI64Load32U_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load8S_0(v *Value) bool {
 	// match: (I64Load8S [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load8S [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5393,7 +5393,7 @@ func rewriteValueWasm_OpWasmI64Load8S_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load8S)
@@ -5406,7 +5406,7 @@ func rewriteValueWasm_OpWasmI64Load8S_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Load8U_0(v *Value) bool {
 	// match: (I64Load8U [off] (I64AddConst [off2] ptr) mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Load8U [off+off2] ptr mem)
 	for {
 		off := v.AuxInt
@@ -5418,7 +5418,7 @@ func rewriteValueWasm_OpWasmI64Load8U_0(v *Value) bool {
 		off2 := v_0.AuxInt
 		ptr := v_0.Args[0]
 		mem := v.Args[1]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Load8U)
@@ -5588,7 +5588,7 @@ func rewriteValueWasm_OpWasmI64Or_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Store_0(v *Value) bool {
 	// match: (I64Store [off] (I64AddConst [off2] ptr) val mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Store [off+off2] ptr val mem)
 	for {
 		off := v.AuxInt
@@ -5601,7 +5601,7 @@ func rewriteValueWasm_OpWasmI64Store_0(v *Value) bool {
 		ptr := v_0.Args[0]
 		val := v.Args[1]
 		mem := v.Args[2]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Store)
@@ -5615,7 +5615,7 @@ func rewriteValueWasm_OpWasmI64Store_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Store16_0(v *Value) bool {
 	// match: (I64Store16 [off] (I64AddConst [off2] ptr) val mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Store16 [off+off2] ptr val mem)
 	for {
 		off := v.AuxInt
@@ -5628,7 +5628,7 @@ func rewriteValueWasm_OpWasmI64Store16_0(v *Value) bool {
 		ptr := v_0.Args[0]
 		val := v.Args[1]
 		mem := v.Args[2]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Store16)
@@ -5642,7 +5642,7 @@ func rewriteValueWasm_OpWasmI64Store16_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Store32_0(v *Value) bool {
 	// match: (I64Store32 [off] (I64AddConst [off2] ptr) val mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Store32 [off+off2] ptr val mem)
 	for {
 		off := v.AuxInt
@@ -5655,7 +5655,7 @@ func rewriteValueWasm_OpWasmI64Store32_0(v *Value) bool {
 		ptr := v_0.Args[0]
 		val := v.Args[1]
 		mem := v.Args[2]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Store32)
@@ -5669,7 +5669,7 @@ func rewriteValueWasm_OpWasmI64Store32_0(v *Value) bool {
 }
 func rewriteValueWasm_OpWasmI64Store8_0(v *Value) bool {
 	// match: (I64Store8 [off] (I64AddConst [off2] ptr) val mem)
-	// cond: off+off2 >= 0
+	// cond: isU32Bit(off+off2)
 	// result: (I64Store8 [off+off2] ptr val mem)
 	for {
 		off := v.AuxInt
@@ -5682,7 +5682,7 @@ func rewriteValueWasm_OpWasmI64Store8_0(v *Value) bool {
 		ptr := v_0.Args[0]
 		val := v.Args[1]
 		mem := v.Args[2]
-		if !(off+off2 >= 0) {
+		if !(isU32Bit(off + off2)) {
 			break
 		}
 		v.reset(OpWasmI64Store8)
diff --git a/src/cmd/internal/obj/wasm/wasmobj.go b/src/cmd/internal/obj/wasm/wasmobj.go
index 2b7e12a93f1..ca09b3fa0b2 100644
--- a/src/cmd/internal/obj/wasm/wasmobj.go
+++ b/src/cmd/internal/obj/wasm/wasmobj.go
@@ -870,6 +870,9 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 			if p.From.Type != obj.TYPE_CONST {
 				panic("bad type for *Load")
 			}
+			if p.From.Offset > math.MaxUint32 {
+				ctxt.Diag("bad offset in %v", p)
+			}
 			writeUleb128(w, align(p.As))
 			writeUleb128(w, uint64(p.From.Offset))
 
@@ -877,6 +880,9 @@ func assemble(ctxt *obj.Link, s *obj.LSym, newprog obj.ProgAlloc) {
 			if p.To.Offset < 0 {
 				panic("negative offset")
 			}
+			if p.From.Offset > math.MaxUint32 {
+				ctxt.Diag("bad offset in %v", p)
+			}
 			writeUleb128(w, align(p.As))
 			writeUleb128(w, uint64(p.To.Offset))