diff --git a/system/physmem.c b/system/physmem.c
index dc1db3a384..75389064a8 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -1970,10 +1970,12 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
     size = REAL_HOST_PAGE_ALIGN(size);
 
     file_size = get_file_size(fd);
-    if (file_size > offset && file_size < (offset + size)) {
-        error_setg(errp, "backing store size 0x%" PRIx64
-                   " does not match 'size' option 0x" RAM_ADDR_FMT,
-                   file_size, size);
+    if (file_size && file_size < offset + size) {
+        error_setg(errp, "%s backing store size 0x%" PRIx64
+                   " is too small for 'size' option 0x" RAM_ADDR_FMT
+                   " plus 'offset' option 0x%" PRIx64,
+                   memory_region_name(mr), file_size, size,
+                   (uint64_t)offset);
         return NULL;
     }