diff --git a/lld/include/lld/Core/DefinedAtom.h b/lld/include/lld/Core/DefinedAtom.h
index 5fc7a1fff5bd..fb7c44aa1216 100644
--- a/lld/include/lld/Core/DefinedAtom.h
+++ b/lld/include/lld/Core/DefinedAtom.h
@@ -98,8 +98,8 @@ public:
                             // by linker
     mergeAsWeakAndAddressUsed, // Is C++ definition inline definition whose
                                // address was taken.
-    mergeByContent,         // Merge with other constants with same content
     mergeSameNameAndSize,   // Another atom with different size is error
+    mergeByContent,         // Merge with other constants with same content.
   };
 
   enum ContentType {
diff --git a/lld/lib/Core/SymbolTable.cpp b/lld/lib/Core/SymbolTable.cpp
index a6089116da56..add6628096e3 100644
--- a/lld/lib/Core/SymbolTable.cpp
+++ b/lld/lib/Core/SymbolTable.cpp
@@ -113,6 +113,8 @@ static MergeResolution mergeCases[][5] = {
 
 static MergeResolution mergeSelect(DefinedAtom::Merge first,
                                    DefinedAtom::Merge second) {
+  assert(first != DefinedAtom::mergeByContent);
+  assert(second != DefinedAtom::mergeByContent);
   return mergeCases[first][second];
 }