diff --git a/tools/sancov/sancov.cpp b/tools/sancov/sancov.cpp
index acf47b99b9c6b..dca7a5d4d3a98 100644
--- a/tools/sancov/sancov.cpp
+++ b/tools/sancov/sancov.cpp
@@ -606,7 +606,11 @@ class Blacklists {
     if (ClBlacklist.empty())
       return std::unique_ptr<SpecialCaseList>();
 
-    return SpecialCaseList::createOrDie({{ClBlacklist}});
+    std::vector<std::string> Paths;
+    // Newer Xcode/libc++ rejects implicit std::string construction in nested
+    // initializer-list copy-initialization, so build the vector explicitly.
+    Paths.emplace_back(static_cast<std::string>(ClBlacklist));
+    return SpecialCaseList::createOrDie(Paths);
   }
   std::unique_ptr<SpecialCaseList> DefaultBlacklist;
   std::unique_ptr<SpecialCaseList> UserBlacklist;