diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index ba1325f435..1689ffecf8 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -373,6 +373,12 @@ static void riscv_cpu_realize(DeviceState *dev, Error **errp)
                        return;
        }
 
+        if (!cpu->cfg.ext_i && !cpu->cfg.ext_e) {
+            error_setg(errp,
+                       "Either I or E extension must be set");
+                       return;
+       }
+
        if (cpu->cfg.ext_g && !(cpu->cfg.ext_i & cpu->cfg.ext_m &
                                cpu->cfg.ext_a & cpu->cfg.ext_f &
                                cpu->cfg.ext_d)) {