diff --git a/src/index/CompressedBlockPrefiltering.cpp b/src/index/CompressedBlockPrefiltering.cpp
index 7b543d9ce..a2af112c7 100644
--- a/src/index/CompressedBlockPrefiltering.cpp
+++ b/src/index/CompressedBlockPrefiltering.cpp
@@ -67,17 +67,17 @@ static void checkEvalRequirements(const std::vector<BlockMetadata>& input,
       AD_CORRECTNESS_CHECK(getMaskedTriple(b1.lastTriple_) <=
                            getMaskedTriple(b2.lastTriple_));
       return true;
-    } else if (b1.blockIndex_ == b2.blockIndex_) {
+    }
+    if (b1.blockIndex_ == b2.blockIndex_) {
       // Given the previous check detects duplicates in the input, the
       // correctness check here will never evaluate to true.
       // => blockIndex_ assignment issue.
       AD_CORRECTNESS_CHECK(b1 == b2);
-      return false;
     } else {
       AD_CORRECTNESS_CHECK(getMaskedTriple(b1.lastTriple_) >
                            getMaskedTriple(b2.firstTriple_));
-      return false;
     }
+    return false;
   };
   if (!std::ranges::is_sorted(input, checkOrder)) {
     throwRuntimeError("The blocks must be provided in sorted order.");