diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c
index 26c7e4482d..fb8baf64f6 100644
--- a/hw/riscv/virt-acpi-build.c
+++ b/hw/riscv/virt-acpi-build.c
@@ -196,7 +196,7 @@ static void build_rhct(GArray *table_data,
     RISCVCPU *cpu = &s->soc[0].harts[0];
     uint32_t mmu_offset = 0;
     uint8_t satp_mode_max;
-    char *isa;
+    g_autofree char *isa = NULL;
 
     AcpiTable table = { .sig = "RHCT", .rev = 1, .oem_id = s->oem_id,
                         .oem_table_id = s->oem_table_id };