diff --git a/pci/src/vfio.rs b/pci/src/vfio.rs
index 1641b619f..1f1efadfc 100644
--- a/pci/src/vfio.rs
+++ b/pci/src/vfio.rs
@@ -696,8 +696,11 @@ impl VfioCommon {
                         .allocate(
                             restored_bar_addr,
                             region_size,
-                            // SAFETY: FFI call. Trivially safe.
-                            Some(unsafe { sysconf(_SC_PAGESIZE) as GuestUsize }),
+                            Some(std::cmp::max(
+                                // SAFETY: FFI call. Trivially safe.
+                                unsafe { sysconf(_SC_PAGESIZE) as GuestUsize },
+                                region_size,
+                            )),
                         )
                         .ok_or(PciDeviceError::IoAllocationFailed(region_size))?
                 }