diff --git a/core/libs/prx/libkernel/File/src/Stdio.cpp b/core/libs/prx/libkernel/File/src/Stdio.cpp
index f11ab92db7..a124a9cf55 100644
--- a/core/libs/prx/libkernel/File/src/Stdio.cpp
+++ b/core/libs/prx/libkernel/File/src/Stdio.cpp
@@ -768,6 +768,15 @@ int APS5_VABI dup2_nid_postfix(int from, int to) {
 int APS5_VABI flock_nid_postfix(int d, int operation) {
     if (GuestSockets::IsOpen(d)) return PosixFailure(GUEST_EOPNOTSUPP);
     File::RefuseArchivedFile(d, "flock");
+#ifdef _WIN32
+    const auto handle = reinterpret_cast<HANDLE>(WithoutParameterHandler([d] { return ::_get_osfhandle(d); }));
+    if (handle == INVALID_HANDLE_VALUE) return PosixFailure(GUEST_EBADF);
+    if (::GetFileType(handle) == FILE_TYPE_PIPE) return PosixFailure(GUEST_EOPNOTSUPP);
+#else
+    struct stat status;
+    if (::fstat(d, &status) != 0) return PosixFailure(GUEST_EBADF);
+    if (S_ISFIFO(status.st_mode)) return PosixFailure(GUEST_EOPNOTSUPP);
+#endif
     const int type = operation & 8 ? 8 : operation & 2 ? 2 : operation & 1 ? 1 : 0;
     if (type == 0) return PosixFailure(GUEST_EBADF);
     if (NativeFlock(d, type | (operation & 4)) != 0) {
diff --git a/core/libs/tests/GuestFilesystem.cpp b/core/libs/tests/GuestFilesystem.cpp
index aab32dc3ec..e259daf878 100644
--- a/core/libs/tests/GuestFilesystem.cpp
+++ b/core/libs/tests/GuestFilesystem.cpp
@@ -981,6 +981,13 @@ int main() {
     Require(flock_nid_postfix(other, 2 | 4) == 0);
     Require(flock_nid_postfix(other, 8) == 0);
     Require(flock_nid_postfix(locked, 2 | 4) == 0);
+    Require(flock_nid_postfix(-1, 2 | 4) == -1 && *__error_nid_postfix() == 9);
+    Require(flock_nid_postfix(0x7fffffff, 1) == -1 && *__error_nid_postfix() == 9);
+    int flockPipe[2] = {-1, -1};
+    Require(pipe_nid_postfix(flockPipe) == 0);
+    Require(flock_nid_postfix(flockPipe[0], 2 | 4) == -1 && *__error_nid_postfix() == 45);
+    Require(flock_nid_postfix(flockPipe[1], 8) == -1 && *__error_nid_postfix() == 45);
+    Require(close_nid_postfix(flockPipe[0]) == 0 && close_nid_postfix(flockPipe[1]) == 0);
     Require(close_nid_postfix(locked) == 0);
     const int recycled = open_nid_postfix(presentName.c_str(), 0, 0);
     Require(recycled >= 0 && flock_nid_postfix(recycled, 8) == 0);