diff --git a/src/blockencodings.h b/src/blockencodings.h
index b980e9e286..349fcbd50f 100644
--- a/src/blockencodings.h
+++ b/src/blockencodings.h
@@ -53,11 +53,11 @@ public:
             }
 
             uint16_t offset = 0;
-            for (size_t i = 0; i < indexes.size(); i++) {
-                if (uint64_t(indexes[i]) + uint64_t(offset) > std::numeric_limits<uint16_t>::max())
+            for (size_t j = 0; j < indexes.size(); j++) {
+                if (uint64_t(indexes[j]) + uint64_t(offset) > std::numeric_limits<uint16_t>::max())
                     throw std::ios_base::failure("indexes overflowed 16 bits");
-                indexes[i] = indexes[i] + offset;
-                offset = indexes[i] + 1;
+                indexes[j] = indexes[j] + offset;
+                offset = indexes[j] + 1;
             }
         } else {
             for (size_t i = 0; i < indexes.size(); i++) {