diff --git a/src/posix/platform/udp.cpp b/src/posix/platform/udp.cpp
index 8993ca1b9..5151f51fd 100644
--- a/src/posix/platform/udp.cpp
+++ b/src/posix/platform/udp.cpp
@@ -240,7 +240,10 @@ otError otPlatUdpClose(otUdpSocket *aUdpSocket)
     otError error = OT_ERROR_NONE;
     int     fd;
 
-    VerifyOrExit(aUdpSocket->mHandle != nullptr, error = OT_ERROR_INVALID_ARGS);
+    // Only call `close()` on platform UDP sockets.
+    // Platform UDP sockets always have valid `mHandle` upon creation.
+    VerifyOrExit(aUdpSocket->mHandle != nullptr);
+
     fd = FdFromHandle(aUdpSocket->mHandle);
     VerifyOrExit(0 == close(fd), error = OT_ERROR_FAILED);