diff --git a/lib/wasm/go_wasip1_wasm_exec b/lib/wasm/go_wasip1_wasm_exec
index 3b2d12ec45..2de1758793 100755
--- a/lib/wasm/go_wasip1_wasm_exec
+++ b/lib/wasm/go_wasip1_wasm_exec
@@ -14,7 +14,7 @@ case "$GOWASIRUNTIME" in
 		exec wazero run -mount /:/ -env-inherit -cachedir "${TMPDIR:-/tmp}"/wazero ${GOWASIRUNTIMEARGS:-} "$1" "${@:2}"
 		;;
 	"wasmtime" | "")
-		exec wasmtime run --dir=/ --env PWD="$PWD" --env PATH="$PATH" -W max-wasm-stack=1048576 ${GOWASIRUNTIMEARGS:-} "$1" "${@:2}"
+		exec wasmtime run --dir=/ --env PWD="$PWD" --env PATH="$PATH" -W max-wasm-stack=8388608 ${GOWASIRUNTIMEARGS:-} "$1" "${@:2}"
 		;;
 	*)
 		echo "Unknown Go WASI runtime specified: $GOWASIRUNTIME"
diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index c2eaeb1248..aa09d1eba3 100644
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -743,6 +743,15 @@ func (t *tester) registerTests() {
 		}
 	}
 
+	// Test GOEXPERIMENT=jsonv2.
+	if !strings.Contains(goexperiment, "jsonv2") {
+		t.registerTest("GOEXPERIMENT=jsonv2 go test encoding/json/...", &goTest{
+			variant: "jsonv2",
+			env:     []string{"GOEXPERIMENT=jsonv2"},
+			pkg:     "encoding/json/...",
+		})
+	}
+
 	// Test ios/amd64 for the iOS simulator.
 	if goos == "darwin" && goarch == "amd64" && t.cgoEnabled {
 		t.registerTest("GOOS=ios on darwin/amd64",