diff --git a/test/run-tests.c b/test/run-tests.c
index 511707494..9c2574ebf 100644
--- a/test/run-tests.c
+++ b/test/run-tests.c
@@ -214,7 +214,10 @@ static int maybe_run_test(int argc, char **argv) {
 #ifdef _WIN32
     DWORD flags;
     HMODULE kernelbase_module;
-    sCompareObjectHandles pCompareObjectHandles; /* function introduced in Windows 10 */
+    union {
+      FARPROC proc;
+      sCompareObjectHandles pCompareObjectHandles; /* Windows >= 10 */
+    } u;
 #endif
     notify_parent_process();
     ASSERT_EQ(sizeof(closed_fd), read(0, &closed_fd, sizeof(closed_fd)));
@@ -224,10 +227,9 @@ static int maybe_run_test(int argc, char **argv) {
     ASSERT_GT((intptr_t) open_fd, 0);
     ASSERT_NE(0, GetHandleInformation(open_fd, &flags));
     kernelbase_module = GetModuleHandleW(L"kernelbase.dll");
-    pCompareObjectHandles = (sCompareObjectHandles)
-        GetProcAddress(kernelbase_module, "CompareObjectHandles");
-    ASSERT_NE(pCompareObjectHandles == NULL || \
-              !pCompareObjectHandles(open_fd, closed_fd), 0);
+    u.proc = GetProcAddress(kernelbase_module, "CompareObjectHandles");
+    if (u.pCompareObjectHandles != NULL)
+      ASSERT_EQ(FALSE, u.pCompareObjectHandles(open_fd, closed_fd));
 #else
     ASSERT_GT(open_fd, 2);
     ASSERT_GT(closed_fd, 2);
diff --git a/test/test-spawn.c b/test/test-spawn.c
index 0dad9bcdc..eaaa8bbea 100644
--- a/test/test-spawn.c
+++ b/test/test-spawn.c
@@ -1678,7 +1678,10 @@ TEST_IMPL(spawn_fs_open) {
 #ifdef _WIN32
   const char dev_null[] = "NUL";
   HMODULE kernelbase_module;
-  sCompareObjectHandles pCompareObjectHandles; /* function introduced in Windows 10 */
+  union {
+    FARPROC proc;
+    sCompareObjectHandles pCompareObjectHandles; /* Windows >= 10 */
+  } u;
 #else
   const char dev_null[] = "/dev/null";
 #endif
@@ -1702,11 +1705,9 @@ TEST_IMPL(spawn_fs_open) {
   ASSERT_NE(0, DuplicateHandle(GetCurrentProcess(), fd, GetCurrentProcess(), &dup_fd,
                                0, /* inherit */ TRUE, DUPLICATE_SAME_ACCESS));
   kernelbase_module = GetModuleHandleW(L"kernelbase.dll");
-  pCompareObjectHandles = (sCompareObjectHandles)
-      GetProcAddress(kernelbase_module, "CompareObjectHandles");
-  ASSERT_NE(pCompareObjectHandles == NULL ||
-            pCompareObjectHandles(fd, dup_fd),
-            0);
+  u.proc = GetProcAddress(kernelbase_module, "CompareObjectHandles");
+  if (u.pCompareObjectHandles != NULL)
+    ASSERT_EQ(TRUE, u.pCompareObjectHandles(fd, dup_fd));
 #else
   dup_fd = dup(fd);
 #endif