diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 70ae3cfde6e3..33928b90fd3f 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1556,6 +1556,7 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
     PCDIMMDevice *dimm = PC_DIMM(dev);
     PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
     MemoryRegion *mr = ddc->get_memory_region(dimm);
+    uint64_t align = TARGET_PAGE_SIZE;
     uint64_t addr;
 
     addr = object_property_get_int(OBJECT(dimm), PC_DIMM_ADDR_PROP, &local_err);
@@ -1565,7 +1566,7 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
 
     addr = pc_dimm_get_free_addr(pcms->hotplug_memory_base,
                                  memory_region_size(&pcms->hotplug_memory),
-                                 !addr ? NULL : &addr,
+                                 !addr ? NULL : &addr, align,
                                  memory_region_size(mr), &local_err);
     if (local_err) {
         goto out;
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index a800ea7a9fde..4944f0faf9d4 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -139,7 +139,7 @@ static int pc_dimm_built_list(Object *obj, void *opaque)
 
 uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
                                uint64_t address_space_size,
-                               uint64_t *hint, uint64_t size,
+                               uint64_t *hint, uint64_t align, uint64_t size,
                                Error **errp)
 {
     GSList *list = NULL, *item;
@@ -152,6 +152,18 @@ uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
         goto out;
     }
 
+    if (hint && QEMU_ALIGN_UP(*hint, align) != *hint) {
+        error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
+                   align);
+        goto out;
+    }
+
+    if (QEMU_ALIGN_UP(size, align) != size) {
+        error_setg(errp, "backend memory size must be multiple of 0x%"
+                   PRIx64, align);
+        goto out;
+    }
+
     assert(address_space_end > address_space_start);
     object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &list);
 
diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
index 761eeef80151..e1dcbbcd5876 100644
--- a/include/hw/mem/pc-dimm.h
+++ b/include/hw/mem/pc-dimm.h
@@ -72,7 +72,7 @@ typedef struct PCDIMMDeviceClass {
 
 uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
                                uint64_t address_space_size,
-                               uint64_t *hint, uint64_t size,
+                               uint64_t *hint, uint64_t align, uint64_t size,
                                Error **errp);
 
 int pc_dimm_get_free_slot(const int *hint, int max_slots, Error **errp);