diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.append.pass.cpp
@@ -11,8 +11,6 @@
 // These tests require locale for non-char paths
 // UNSUPPORTED: libcpp-has-no-localization
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // <filesystem>
 
 // class path
@@ -197,6 +195,9 @@
   // required.
   // On Windows, the append method is more complex and uses intermediate
   // path objects, which causes extra allocations.
+  // In DLL builds on Windows, the overridden operator new won't pick up
+  // allocations done within the DLL, so the RequireAllocationGuard below
+  // won't necessarily see allocations in the cases where they're expected.
 #ifdef _WIN32
   bool DisableAllocations = false;
 #else
@@ -208,6 +209,7 @@
     {
       RequireAllocationGuard  g; // requires 1 or more allocations occur by default
       if (DisableAllocations) g.requireExactly(0);
+      else TEST_ONLY_WIN32(g.requireAtLeast(0));
       LHS /= RHS;
     }
     assert(PathEq(LHS, E));
@@ -219,6 +221,7 @@
     {
       RequireAllocationGuard g;
       if (DisableAllocations) g.requireExactly(0);
+      else TEST_ONLY_WIN32(g.requireAtLeast(0));
       LHS.append(RHS, REnd);
     }
     assert(PathEq(LHS, E));
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.assign/move.pass.cpp
@@ -8,8 +8,6 @@
 
 // UNSUPPORTED: c++03
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // <filesystem>
 
 // class path
@@ -30,7 +28,9 @@
   assert(globalMemCounter.checkOutstandingNewEq(0));
   const std::string s("we really really really really really really really "
                       "really really long string so that we allocate");
-  assert(globalMemCounter.checkOutstandingNewEq(1));
+  // On windows, the operator new from count_new.h can't override the default
+  // operator for calls within the libc++ DLL.
+  TEST_NOT_WIN32(assert(globalMemCounter.checkOutstandingNewEq(1)));
   const fs::path::string_type ps(s.begin(), s.end());
   path p(s);
   {
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.concat.pass.cpp
@@ -11,8 +11,6 @@
 // These tests require locale for non-char paths
 // UNSUPPORTED: libcpp-has-no-localization
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // <filesystem>
 
 // class path
@@ -142,6 +140,10 @@
   // code_cvt conversions.
   // For the path native type, no allocations will be performed because no
   // conversion is required.
+
+  // In DLL builds on Windows, the overridden operator new won't pick up
+  // allocations done within the DLL, so the RequireAllocationGuard below
+  // won't necessarily see allocations in the cases where they're expected.
   bool DisableAllocations = std::is_same<CharT, path::value_type>::value;
   {
     path LHS(L); PathReserve(LHS, ReserveSize);
@@ -149,6 +151,7 @@
     {
       RequireAllocationGuard  g; // requires 1 or more allocations occur by default
       if (DisableAllocations) g.requireExactly(0);
+      else TEST_ONLY_WIN32(g.requireAtLeast(0));
       LHS += RHS;
     }
     assert(LHS == E);
@@ -160,6 +163,7 @@
     {
       RequireAllocationGuard g;
       if (DisableAllocations) g.requireExactly(0);
+      else TEST_ONLY_WIN32(g.requireAtLeast(0));
       LHS.concat(RHS, REnd);
     }
     assert(LHS == E);
diff --git a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
--- a/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
+++ b/libcxx/test/std/input.output/filesystems/class.path/path.member/path.construct/move.pass.cpp
@@ -8,8 +8,6 @@
 
 // UNSUPPORTED: c++03
 
-// XFAIL: LIBCXX-WINDOWS-FIXME
-
 // <filesystem>
 
 // class path
@@ -30,7 +28,9 @@
   assert(globalMemCounter.checkOutstandingNewEq(0));
   const std::string s("we really really really really really really really "
                       "really really long string so that we allocate");
-  assert(globalMemCounter.checkOutstandingNewEq(1));
+  // On windows, the operator new from count_new.h can't override the default
+  // operator for calls within the libc++ DLL.
+  TEST_NOT_WIN32(assert(globalMemCounter.checkOutstandingNewEq(1)));
   const fs::path::string_type ps(s.begin(), s.end());
   path p(s);
   {
diff --git a/libcxx/test/support/test_macros.h b/libcxx/test/support/test_macros.h
--- a/libcxx/test/support/test_macros.h
+++ b/libcxx/test/support/test_macros.h
@@ -374,8 +374,10 @@
 
 #ifdef _WIN32
 #define TEST_NOT_WIN32(...) ((void)0)
+#define TEST_ONLY_WIN32(...) __VA_ARGS__
 #else
 #define TEST_NOT_WIN32(...) __VA_ARGS__
+#define TEST_ONLY_WIN32(...) ((void)0)
 #endif
 
 #if defined(__GNUC__)