diff --git a/src/conf/checkpoint_conf.c b/src/conf/checkpoint_conf.c
index 4731f21aba..175a95fed7 100644
--- a/src/conf/checkpoint_conf.c
+++ b/src/conf/checkpoint_conf.c
@@ -265,6 +265,7 @@ virDomainCheckpointAlignDisks(virDomainCheckpointDef *chkdef)
     virDomainDef *domdef = chkdef->parent.dom;
     g_autoptr(GHashTable) map = virHashNew(NULL);
     g_autofree virDomainCheckpointDiskDef *olddisks = NULL;
+    size_t oldndisks;
     size_t i;
     int checkpoint_default = VIR_DOMAIN_CHECKPOINT_TYPE_NONE;
 
@@ -292,9 +293,14 @@ virDomainCheckpointAlignDisks(virDomainCheckpointDef *chkdef)
     if (!chkdef->ndisks)
         checkpoint_default = VIR_DOMAIN_CHECKPOINT_TYPE_BITMAP;
 
+    olddisks = g_steal_pointer(&chkdef->disks);
+    oldndisks = chkdef->ndisks;
+    chkdef->disks = g_new0(virDomainCheckpointDiskDef, domdef->ndisks);
+    chkdef->ndisks = domdef->ndisks;
+
     /* Double check requested disks.  */
-    for (i = 0; i < chkdef->ndisks; i++) {
-        virDomainCheckpointDiskDef *chkdisk = &chkdef->disks[i];
+    for (i = 0; i < oldndisks; i++) {
+        virDomainCheckpointDiskDef *chkdisk = &olddisks[i];
         virDomainDiskDef *domdisk = virDomainDiskByName(domdef, chkdisk->name, false);
 
         if (!domdisk) {
@@ -328,10 +334,6 @@ virDomainCheckpointAlignDisks(virDomainCheckpointDef *chkdef)
         }
     }
 
-    olddisks = g_steal_pointer(&chkdef->disks);
-    chkdef->disks = g_new0(virDomainCheckpointDiskDef, domdef->ndisks);
-    chkdef->ndisks = domdef->ndisks;
-
     for (i = 0; i < domdef->ndisks; i++) {
         virDomainDiskDef *domdisk = domdef->disks[i];
         virDomainCheckpointDiskDef *chkdisk = chkdef->disks + i;
diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c
index c765e4c815..fc6f0a859d 100644
--- a/src/conf/snapshot_conf.c
+++ b/src/conf/snapshot_conf.c
@@ -636,6 +636,7 @@ virDomainSnapshotAlignDisks(virDomainSnapshotDef *snapdef,
     virDomainDef *domdef = snapdef->parent.dom;
     g_autoptr(GHashTable) map = virHashNew(NULL);
     g_autofree virDomainSnapshotDiskDef *olddisks = NULL;
+    size_t oldndisks;
     size_t i;
 
     if (!domdef) {
@@ -654,9 +655,14 @@ virDomainSnapshotAlignDisks(virDomainSnapshotDef *snapdef,
     if (!domdef->ndisks)
         return 0;
 
+    olddisks = g_steal_pointer(&snapdef->disks);
+    oldndisks = snapdef->ndisks;
+    snapdef->disks = g_new0(virDomainSnapshotDiskDef, domdef->ndisks);
+    snapdef->ndisks = domdef->ndisks;
+
     /* Double check requested disks.  */
-    for (i = 0; i < snapdef->ndisks; i++) {
-        virDomainSnapshotDiskDef *snapdisk = &snapdef->disks[i];
+    for (i = 0; i < oldndisks; i++) {
+        virDomainSnapshotDiskDef *snapdisk = &olddisks[i];
         virDomainDiskDef *domdisk = virDomainDiskByName(domdef, snapdisk->name, false);
 
         if (!domdisk) {
@@ -708,10 +714,6 @@ virDomainSnapshotAlignDisks(virDomainSnapshotDef *snapdef,
         }
     }
 
-    olddisks = g_steal_pointer(&snapdef->disks);
-    snapdef->disks = g_new0(virDomainSnapshotDiskDef, domdef->ndisks);
-    snapdef->ndisks = domdef->ndisks;
-
     for (i = 0; i < domdef->ndisks; i++) {
         virDomainDiskDef *domdisk = domdef->disks[i];
         virDomainSnapshotDiskDef *snapdisk = snapdef->disks + i;