diff --git a/libcxx/modules/std/cmath.cppm b/libcxx/modules/std/cmath.cppm
--- a/libcxx/modules/std/cmath.cppm
+++ b/libcxx/modules/std/cmath.cppm
@@ -140,7 +140,6 @@
   using std::hypotl;
 
   // [c.math.hypot3], three-dimensional hypotenuse
-  using std::hypot;
 
   using std::pow;
   using std::powf;
diff --git a/libcxx/modules/std/filesystem.cppm b/libcxx/modules/std/filesystem.cppm
--- a/libcxx/modules/std/filesystem.cppm
+++ b/libcxx/modules/std/filesystem.cppm
@@ -36,8 +36,6 @@
   using std::filesystem::recursive_directory_iterator;
 
   // [fs.rec.dir.itr.nonmembers], range access for recursive directory iterators
-  using std::filesystem::begin;
-  using std::filesystem::end;
 
   // [fs.class.file.status], file status
   using std::filesystem::file_status;
diff --git a/libcxx/modules/std/iterator.cppm b/libcxx/modules/std/iterator.cppm
--- a/libcxx/modules/std/iterator.cppm
+++ b/libcxx/modules/std/iterator.cppm
@@ -101,8 +101,6 @@
   // [projected], projected
   using std::projected;
 
-  using std::incrementable_traits;
-
   // [alg.req], common algorithm requirements
   // [alg.req.ind.move], concept indirectly_movable
   using std::indirectly_movable;
@@ -210,8 +208,6 @@
 
   using std::common_iterator;
 
-  using std::incrementable_traits;
-
   // [default.sentinel], default sentinel
   using std::default_sentinel;
   using std::default_sentinel_t;
diff --git a/libcxx/modules/std/memory.cppm b/libcxx/modules/std/memory.cppm
--- a/libcxx/modules/std/memory.cppm
+++ b/libcxx/modules/std/memory.cppm
@@ -129,8 +129,6 @@
   using std::make_unique;
   using std::make_unique_for_overwrite;
 
-  using std::swap;
-
   using std::operator<;
   using std::operator>;
   using std::operator<=;
diff --git a/libcxx/modules/std/numbers.cppm b/libcxx/modules/std/numbers.cppm
--- a/libcxx/modules/std/numbers.cppm
+++ b/libcxx/modules/std/numbers.cppm
@@ -26,20 +26,6 @@
   using std::numbers::sqrt2_v;
   using std::numbers::sqrt3_v;
 
-  using std::numbers::e_v;
-  using std::numbers::egamma_v;
-  using std::numbers::inv_pi_v;
-  using std::numbers::inv_sqrt3_v;
-  using std::numbers::inv_sqrtpi_v;
-  using std::numbers::ln10_v;
-  using std::numbers::ln2_v;
-  using std::numbers::log10e_v;
-  using std::numbers::log2e_v;
-  using std::numbers::phi_v;
-  using std::numbers::pi_v;
-  using std::numbers::sqrt2_v;
-  using std::numbers::sqrt3_v;
-
   using std::numbers::e;
   using std::numbers::egamma;
   using std::numbers::inv_pi;
diff --git a/libcxx/modules/std/stack.cppm b/libcxx/modules/std/stack.cppm
--- a/libcxx/modules/std/stack.cppm
+++ b/libcxx/modules/std/stack.cppm
@@ -15,7 +15,6 @@
   // [stack], class template stack
   using std::stack;
 
-  using std::operator==;
   using std::operator==;
   using std::operator!=;
   using std::operator<;
diff --git a/libcxx/modules/std/tuple.cppm b/libcxx/modules/std/tuple.cppm
--- a/libcxx/modules/std/tuple.cppm
+++ b/libcxx/modules/std/tuple.cppm
@@ -38,8 +38,6 @@
   using std::tuple_element;
   using std::tuple_size;
 
-  using std::tuple_element_t;
-
   // [tuple.elem], element access
   using std::get;
   using std::tuple_element_t;
diff --git a/libcxx/modules/std/utility.cppm b/libcxx/modules/std/utility.cppm
--- a/libcxx/modules/std/utility.cppm
+++ b/libcxx/modules/std/utility.cppm
@@ -70,9 +70,6 @@
   using std::tuple_element;
   using std::tuple_size;
 
-  using std::tuple_element;
-  using std::tuple_size;
-
   using std::get;
 
   // [pair.piecewise], pair piecewise construction
diff --git a/libcxx/test/tools/clang_tidy_checks/header_exportable_declarations.cpp b/libcxx/test/tools/clang_tidy_checks/header_exportable_declarations.cpp
--- a/libcxx/test/tools/clang_tidy_checks/header_exportable_declarations.cpp
+++ b/libcxx/test/tools/clang_tidy_checks/header_exportable_declarations.cpp
@@ -112,7 +112,6 @@
 
   switch (file_type_) {
   case FileType::Header:
-
     finder->addMatcher(
         namedDecl(
             // Looks at the common locations where headers store their data
@@ -229,8 +228,16 @@
       if (clang::Module* M = decl->getOwningModule(); M && M->Kind != clang::Module::ModulePartitionInterface)
         return;
 
-    if (decls_.contains(name))
-      return;
+    if (decls_.contains(name)) {
+      // For modules avoid exporting the same named declaration twice. For
+      // header files this is common and valid.
+      if (file_type_ == FileType::ModulePartition)
+        // After the warning the script continues.
+        // The test will fail since modules have duplicated entries and headers not.
+        llvm::errs() << "Duplicated export of '" << name << "'.\n";
+      else
+        return;
+    }
 
     std::cout << "using " << std::string{name} << ";\n";
     decls_.insert(name);