diff --git a/lucene/CHANGES.txt b/lucene/CHANGES.txt
index 62c0c0f5ab8..e486cdd0164 100644
--- a/lucene/CHANGES.txt
+++ b/lucene/CHANGES.txt
@@ -124,6 +124,11 @@ Bug Fixes
 * LUCENE-6918: LRUQueryCache.onDocIdSetEviction is only called when at least
   one DocIdSet is being evicted. (Adrien Grand)
 
+* LUCENE-6910: fix 'if ... > Integer.MAX_VALUE' check in
+  (Binary|Numeric)DocValuesFieldUpdates.merge
+  (https://scan.coverity.com/projects/5620 CID 119973 and CID 120081)
+  (Christine Poerschke, Coverity Scan (via Rishabh Patel))
+
 ======================= Lucene 5.4.0 =======================
 
 New Features
diff --git a/lucene/core/src/java/org/apache/lucene/index/BinaryDocValuesFieldUpdates.java b/lucene/core/src/java/org/apache/lucene/index/BinaryDocValuesFieldUpdates.java
index a5b817f0509..684afefbbbc 100644
--- a/lucene/core/src/java/org/apache/lucene/index/BinaryDocValuesFieldUpdates.java
+++ b/lucene/core/src/java/org/apache/lucene/index/BinaryDocValuesFieldUpdates.java
@@ -169,12 +169,12 @@ class BinaryDocValuesFieldUpdates extends DocValuesFieldUpdates {
   @Override
   public void merge(DocValuesFieldUpdates other) {
     BinaryDocValuesFieldUpdates otherUpdates = (BinaryDocValuesFieldUpdates) other;
-    int newSize = size  + otherUpdates.size;
-    if (newSize > Integer.MAX_VALUE) {
+    if (otherUpdates.size > Integer.MAX_VALUE - size) {
       throw new IllegalStateException(
           "cannot support more than Integer.MAX_VALUE doc/value entries; size="
               + size + " other.size=" + otherUpdates.size);
     }
+    final int newSize = size  + otherUpdates.size;
     docs = docs.grow(newSize);
     offsets = offsets.grow(newSize);
     lengths = lengths.grow(newSize);
diff --git a/lucene/core/src/java/org/apache/lucene/index/NumericDocValuesFieldUpdates.java b/lucene/core/src/java/org/apache/lucene/index/NumericDocValuesFieldUpdates.java
index dd6e8599317..641c594d388 100644
--- a/lucene/core/src/java/org/apache/lucene/index/NumericDocValuesFieldUpdates.java
+++ b/lucene/core/src/java/org/apache/lucene/index/NumericDocValuesFieldUpdates.java
@@ -144,7 +144,7 @@ class NumericDocValuesFieldUpdates extends DocValuesFieldUpdates {
   public void merge(DocValuesFieldUpdates other) {
     assert other instanceof NumericDocValuesFieldUpdates;
     NumericDocValuesFieldUpdates otherUpdates = (NumericDocValuesFieldUpdates) other;
-    if (size  + otherUpdates.size > Integer.MAX_VALUE) {
+    if (otherUpdates.size > Integer.MAX_VALUE - size) {
       throw new IllegalStateException(
           "cannot support more than Integer.MAX_VALUE doc/value entries; size="
               + size + " other.size=" + otherUpdates.size);