diff --git a/test/SerialIOTest.cpp b/test/SerialIOTest.cpp
index 6abbce6e19..d5fc962a1c 100644
--- a/test/SerialIOTest.cpp
+++ b/test/SerialIOTest.cpp
@@ -3929,6 +3929,14 @@ TEST_CASE("git_adios2_early_chunk_query", "[serial][adios2]")
         R"({"backend": "adios2"})");
 }
 
+/*
+ * Require Gnu compiler 11 or younger because this test needs the
+ * <filesystem> header.
+ */
+#if __GNUC__ >= 11 &&                                                          \
+    ADIOS2_VERSION_MAJOR * 1000000000 + ADIOS2_VERSION_MINOR * 100000000 +     \
+            ADIOS2_VERSION_PATCH * 1000000 + ADIOS2_VERSION_TWEAK >=           \
+        2701001223
 void adios2_bp5_flush(std::string const &cfg, bool flushDuringStep)
 {
     constexpr size_t size = 1024 * 1024 * 1024;
@@ -4010,14 +4018,6 @@ void adios2_bp5_flush(std::string const &cfg, bool flushDuringStep)
 
 TEST_CASE("adios2_bp5_flush", "[serial][adios2]")
 {
-    /*
-     * Require Gnu compiler 11 or younger because this test needs the
-     * <filesystem> header.
-     */
-#if __GNUC__ >= 11 &&                                                          \
-    ADIOS2_VERSION_MAJOR * 1000000000 + ADIOS2_VERSION_MINOR * 100000000 +     \
-            ADIOS2_VERSION_PATCH * 1000000 + ADIOS2_VERSION_TWEAK >=           \
-        2701001223
     std::string cfg1 = R"(
 [adios2]
 
@@ -4071,9 +4071,8 @@ BufferChunkSize = 2147483646 # 2^31 - 2
 )";
 
     adios2_bp5_flush(cfg3, /* flushDuringStep = */ true);
-
-#endif
 }
+#endif
 
 TEST_CASE("serial_adios2_backend_config", "[serial][adios2]")
 {