diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index d7654120d115060e48aa26293f4e9973d4e5f999..04b7fbf2c80cafc87a96f7ac3247c6df84d33c75 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -857,6 +857,7 @@ typedef enum {
     VIR_DOMAIN_MEM_CURRENT = 0,        /* affect current domain state */
     VIR_DOMAIN_MEM_LIVE    = (1 << 0), /* affect active domain */
     VIR_DOMAIN_MEM_CONFIG  = (1 << 1), /* affect next boot */
+    VIR_DOMAIN_MEM_MAXIMUM = (1 << 2), /* affect Max rather than current */
 } virDomainMemoryModFlags;
 
 
diff --git a/src/libvirt.c b/src/libvirt.c
index abde7db80bdbca66a349582ce18c02d562b4241f..4a396955bac6f1e5905989bbed8504e0d6701893 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -2832,6 +2832,8 @@ error:
  * (that is, @flags is VIR_DOMAIN_MEM_CURRENT), then an inactive domain
  * modifies persistent setup, while an active domain is hypervisor-dependent
  * on whether just live or both live and persistent state is changed.
+ * If VIR_DOMAIN_MEM_MAXIMUM is set, the change affects domain's maximum memory
+ * size rather than current memory size.
  * Not all hypervisors can support all flag combinations.
  *
  * Returns 0 in case of success, -1 in case of failure.