diff --git a/device/cluster.cpp b/device/cluster.cpp
index 710bce67..20969005 100644
--- a/device/cluster.cpp
+++ b/device/cluster.cpp
@@ -1339,7 +1339,7 @@ void Cluster::configure_tlb(
         tlb_config_map.insert({logical_device_id, {}});
         map_core_to_tlb_per_chip.insert({logical_device_id, {}});
     }
-    log_assert(tlb_config_map.find(tlb_index) == tlb_config_map.end(), "TLB index already configured {}", tlb_index);
+    log_assert(tlb_config_map.find(tlb_index) != tlb_config_map.end(), "TLB index already configured {}", tlb_index);
 
     TTDevice* tt_device = get_tt_device(logical_device_id);
     tt_device->set_dynamic_tlb(tlb_index, core, address, harvested_coord_translation.at(logical_device_id), ordering);