diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index 56bff00055..b7ab12ee0d 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1194,7 +1194,7 @@ StringObjectException Print::validate(StringObjectException *warning, Polygons*
         }
     }
 
-    if (m_config.print_sequence == PrintSequence::ByObject && m_objects.size() > 1) {
+    if (m_config.print_sequence == PrintSequence::ByObject && (m_objects.size() > 1 || m_objects[0]->instances().size() > 1)) {
         if (m_config.timelapse_type == TimelapseType::tlSmooth)
             return {L("Smooth mode of timelapse is not supported when \"by object\" sequence is enabled.")};