diff --git a/.changelogs/1.1.11/335_fix_affinity_matrix_prevalidation.yml b/.changelogs/1.1.11/335_fix_affinity_matrix_prevalidation.yml
new file mode 100644
index 0000000..4bb618e
--- /dev/null
+++ b/.changelogs/1.1.11/335_fix_affinity_matrix_prevalidation.yml
@@ -0,0 +1,2 @@
+fixed:
+  - Fixed affinity matrix pre-validation by inverting validations (@Thalagyrt). [#335]
diff --git a/proxlb/models/calculations.py b/proxlb/models/calculations.py
index 8e6e73f..3165e71 100644
--- a/proxlb/models/calculations.py
+++ b/proxlb/models/calculations.py
@@ -605,7 +605,7 @@ class Calculations:
             logger.debug(f"Affinity for guest {guest} is {'valid' if balancing_state_affinity else 'NOT valid'}")
             logger.debug(f"Anti-affinity for guest {guest} is {'valid' if balancing_state_anti_affinity else 'NOT valid'}")
 
-            balancing_ok = not balancing_state_affinity or not balancing_state_anti_affinity
+            balancing_ok = balancing_state_affinity and balancing_state_anti_affinity
 
         if balancing_ok:
             logger.debug(f"Rebalancing based on affinity/anti-affinity map is not required.")