diff --git a/src/qemu/qemu_capabilities.c b/src/qemu/qemu_capabilities.c
index 3bf66afb8b..3d729099e9 100644
--- a/src/qemu/qemu_capabilities.c
+++ b/src/qemu/qemu_capabilities.c
@@ -642,6 +642,7 @@ VIR_ENUM_IMPL(virQEMUCaps,
 
               /* 410 */
               "virtio-mem-pci", /* QEMU_CAPS_DEVICE_VIRTIO_MEM_PCI */
+              "memory-backend-file.reserve", /* QEMU_CAPS_MEMORY_BACKEND_RESERVE */
     );
 
 
@@ -1720,6 +1721,7 @@ static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsMemoryBackendFile[] =
      * supported. The 'x-' prefix was kept for compatibility with already
      * released qemu versions. */
     { "x-use-canonical-path-for-ramblock-id", QEMU_CAPS_X_USE_CANONICAL_PATH_FOR_RAMBLOCK_ID },
+    { "reserve", QEMU_CAPS_MEMORY_BACKEND_RESERVE },
 };
 
 static struct virQEMUCapsStringFlags virQEMUCapsObjectPropsMemoryBackendMemfd[] = {
diff --git a/src/qemu/qemu_capabilities.h b/src/qemu/qemu_capabilities.h
index 0b4ce4a4f4..6d544e92c4 100644
--- a/src/qemu/qemu_capabilities.h
+++ b/src/qemu/qemu_capabilities.h
@@ -622,6 +622,7 @@ typedef enum { /* virQEMUCapsFlags grouping marker for syntax-check */
 
     /* 410 */
     QEMU_CAPS_DEVICE_VIRTIO_MEM_PCI, /* -device virtio-mem-pci */
+    QEMU_CAPS_MEMORY_BACKEND_RESERVE, /* -object memory-backend-*.reserve= */
 
     QEMU_CAPS_LAST /* this must always be the last item */
 } virQEMUCapsFlags;
diff --git a/tests/qemucapabilitiesdata/caps_6.1.0.x86_64.xml b/tests/qemucapabilitiesdata/caps_6.1.0.x86_64.xml
index 6083051633..518c0cea77 100644
--- a/tests/qemucapabilitiesdata/caps_6.1.0.x86_64.xml
+++ b/tests/qemucapabilitiesdata/caps_6.1.0.x86_64.xml
@@ -241,6 +241,7 @@
   <flag name='set-action'/>
   <flag name='virtio-blk.queue-size'/>
   <flag name='virtio-mem-pci'/>
+  <flag name='memory-backend-file.reserve'/>
   <version>6001000</version>
   <kvmVersion>0</kvmVersion>
   <microcodeVersion>43100243</microcodeVersion>