diff --git a/modules/dcache-qos/src/main/java/org/dcache/qos/services/verifier/handlers/FileStatusVerifier.java b/modules/dcache-qos/src/main/java/org/dcache/qos/services/verifier/handlers/FileStatusVerifier.java
index 412cf919b82..8a9e31d3530 100644
--- a/modules/dcache-qos/src/main/java/org/dcache/qos/services/verifier/handlers/FileStatusVerifier.java
+++ b/modules/dcache-qos/src/main/java/org/dcache/qos/services/verifier/handlers/FileStatusVerifier.java
@@ -87,6 +87,7 @@ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 import org.dcache.cells.CellStub;
 import org.dcache.qos.data.FileQoSRequirements;
 import org.dcache.qos.data.QoSAction;
+import org.dcache.qos.data.QoSMessageType;
 import org.dcache.qos.services.verifier.data.PoolInfoMap;
 import org.dcache.qos.services.verifier.data.VerifiedLocations;
 import org.dcache.qos.services.verifier.data.VerifyOperation;
@@ -449,6 +450,18 @@ private Optional<QoSAction> checkForLocationAdjustment(FileQoSRequirements requi
             }
         }
 
+        // REVISIT: effectively disable adjustment if we need to reduce the number of replicas.
+        //
+        // This section is added due to race condition between PIN and UNPIN operations, which
+        // may lead to PIN and UNPIN requests processed out of order. Thus UNPIN, followed by PIN, with
+        // expected result in file being pinned may be processed as PIN followed by UNPIN, with
+        // file ending in unpinned state.
+        //
+         // The redundant pinned copy will be reduced by scanner at the next run.
+        if (missing < 0 && operation.getMessageType() != QoSMessageType.SYSTEM_SCAN) {
+            missing = 0;
+        }
+
         operation.setNeeded(Math.abs(missing));
 
         LOGGER.debug("{}, checkForLocationAdjustment; required {}, excluded {}, missing {}.",