diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index d3c2cd9fc0f..137702c1525 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -953,11 +953,15 @@ static void qt_ignore_sigpipe()
 {
     // Set to ignore SIGPIPE once only.
     static QBasicAtomicInt atom = Q_BASIC_ATOMIC_INITIALIZER(0);
-    if (atom.testAndSetRelaxed(0, 1)) {
+    if (!atom.load()) {
+        // More than one thread could turn off SIGPIPE at the same time
+        // But that's acceptable because they all would be doing the same
+        // action
         struct sigaction noaction;
         memset(&noaction, 0, sizeof(noaction));
         noaction.sa_handler = SIG_IGN;
         ::sigaction(SIGPIPE, &noaction, 0);
+        atom.store(1);
     }
 }
 
diff --git a/src/network/socket/qnativesocketengine_unix.cpp b/src/network/socket/qnativesocketengine_unix.cpp
index 4b22f1c262e..c73bbed088f 100644
--- a/src/network/socket/qnativesocketengine_unix.cpp
+++ b/src/network/socket/qnativesocketengine_unix.cpp
@@ -103,11 +103,15 @@ static void qt_ignore_sigpipe()
 #ifndef Q_NO_POSIX_SIGNALS
     // Set to ignore SIGPIPE once only.
     static QBasicAtomicInt atom = Q_BASIC_ATOMIC_INITIALIZER(0);
-    if (atom.testAndSetRelaxed(0, 1)) {
+    if (!atom.load()) {
+        // More than one thread could turn off SIGPIPE at the same time
+        // But that's acceptable because they all would be doing the same
+        // action
         struct sigaction noaction;
         memset(&noaction, 0, sizeof(noaction));
         noaction.sa_handler = SIG_IGN;
         ::sigaction(SIGPIPE, &noaction, 0);
+        atom.store(1);
     }
 #else
     // Posix signals are not supported by the underlying platform