diff --git a/libcxx/test/libcxx/containers/views/mdspan/layout_left/assert.stride.pass.cpp b/libcxx/test/libcxx/containers/views/mdspan/layout_left/assert.stride.pass.cpp
index 96af460d695db..e54cf8678ea71 100644
--- a/libcxx/test/libcxx/containers/views/mdspan/layout_left/assert.stride.pass.cpp
+++ b/libcxx/test/libcxx/containers/views/mdspan/layout_left/assert.stride.pass.cpp
@@ -35,7 +35,7 @@ int main(int, char**) {
   {
     std::layout_left::mapping<std::dextents<int, 3>> m{std::dextents<int, 3>{100, 100, 100}};
 
-    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "invalid rank index");
+    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "layout_left::mapping::stride(): invalid rank index");
   }
   return 0;
 }
diff --git a/libcxx/test/libcxx/containers/views/mdspan/layout_right/assert.stride.pass.cpp b/libcxx/test/libcxx/containers/views/mdspan/layout_right/assert.stride.pass.cpp
index fe5376b480c08..9cc5ad72f9349 100644
--- a/libcxx/test/libcxx/containers/views/mdspan/layout_right/assert.stride.pass.cpp
+++ b/libcxx/test/libcxx/containers/views/mdspan/layout_right/assert.stride.pass.cpp
@@ -35,7 +35,7 @@ int main(int, char**) {
   {
     std::layout_right::mapping<std::dextents<int, 3>> m{std::dextents<int, 3>{100, 100, 100}};
 
-    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "invalid rank index");
+    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "layout_right::mapping::stride(): invalid rank index");
   }
   return 0;
 }
diff --git a/libcxx/test/libcxx/containers/views/mdspan/layout_stride/assert.stride.pass.cpp b/libcxx/test/libcxx/containers/views/mdspan/layout_stride/assert.stride.pass.cpp
index b3b69549b2ebe..5ae141389da4e 100644
--- a/libcxx/test/libcxx/containers/views/mdspan/layout_stride/assert.stride.pass.cpp
+++ b/libcxx/test/libcxx/containers/views/mdspan/layout_stride/assert.stride.pass.cpp
@@ -30,7 +30,7 @@ int main(int, char**) {
     std::layout_stride::mapping<std::dextents<int, 3>> m(
         std::dextents<int, 3>(100, 100, 100), std::array<int, 3>{1, 100, 10000});
 
-    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "invalid rank index");
+    TEST_LIBCPP_ASSERT_FAILURE(m.stride(4), "layout_stride::mapping::stride(): invalid rank index");
   }
   return 0;
 }
diff --git a/libcxx/test/support/check_assertion.h b/libcxx/test/support/check_assertion.h
index 98dd95b11556e..01e296d9138d0 100644
--- a/libcxx/test/support/check_assertion.h
+++ b/libcxx/test/support/check_assertion.h
@@ -89,8 +89,7 @@ struct AssertionInfoMatcher {
     std::size_t found_at = got_msg.find(msg_);
     if (found_at == std::string_view::npos)
       return false;
-    // Allow any match
-    return true;
+    return found_at == 0 && got_msg.size() == msg_.size();
   }
 private:
   bool is_empty_;