diff --git a/device_tree.c b/device_tree.c
index 0e7fe2dda6..10cf3d0b60 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -240,11 +240,8 @@ uint32_t qemu_devtree_alloc_phandle(void *fdt)
      * which phandle id to start allocting phandles.
      */
     if (!phandle) {
-        const char *phandle_start = qemu_opt_get(qemu_get_machine_opts(),
-                                                 "phandle_start");
-        if (phandle_start) {
-            phandle = strtoul(phandle_start, NULL, 0);
-        }
+        phandle = qemu_opt_get_number(qemu_get_machine_opts(),
+                                      "phandle_start", 0);
     }
 
     if (!phandle) {
diff --git a/vl.c b/vl.c
index fb69f226e1..bea1a10cc6 100644
--- a/vl.c
+++ b/vl.c
@@ -409,7 +409,7 @@ static QemuOptsList qemu_machine_opts = {
             .help = "Dump current dtb to a file and quit",
         }, {
             .name = "phandle_start",
-            .type = QEMU_OPT_STRING,
+            .type = QEMU_OPT_NUMBER,
             .help = "The first phandle ID we may generate dynamically",
         }, {
             .name = "dt_compatible",