diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index b7c7c4bab41..7cd379f9fd2 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -660,6 +660,11 @@ static void applyProcessParameters(const QProcess::UnixProcessParameters &params
             if (!ignore_sigpipe || sig != SIGPIPE)
                 QtVforkSafe::sigaction(sig, &sa, nullptr);
         }
+
+        // and unmask all signals
+        sigset_t set;
+        sigemptyset(&set);
+        sigprocmask(SIG_SETMASK, &set, nullptr);
     }
 
     // Close all file descriptors above stderr.
diff --git a/tests/auto/corelib/io/qprocess/testUnixProcessParameters/main.cpp b/tests/auto/corelib/io/qprocess/testUnixProcessParameters/main.cpp
index e701677403d..9be19306677 100644
--- a/tests/auto/corelib/io/qprocess/testUnixProcessParameters/main.cpp
+++ b/tests/auto/corelib/io/qprocess/testUnixProcessParameters/main.cpp
@@ -30,17 +30,30 @@ int main(int argc, char **argv)
     }
 
     if (cmd == "reset-sighand") {
-        // confirm it was not ignored
+        bool ok = true;
+
+        // confirm our signal block mask is empty
+        sigset_t set;
+        sigprocmask(SIG_SETMASK, nullptr, &set);
+        for (int signo = 1; signo < NSIG; ++signo) {
+            if (sigismember(&set, signo)) {
+                fprintf(stderr, "'%s' is blocked.\n", strsignal(signo));
+                ok = false;
+            }
+        }
+
+        // confirm SIGUSR1 was not ignored
         struct sigaction action;
         sigaction(SIGUSR1, nullptr, &action);
-        if (action.sa_handler == SIG_DFL)
-            return EXIT_SUCCESS;
-        fprintf(stderr, "SIGUSR1 is SIG_IGN\n");
-        return EXIT_FAILURE;
+        if (action.sa_handler != SIG_DFL) {
+            fprintf(stderr, "SIGUSR1 is SIG_IGN\n");
+            ok = false;
+        }
+        return ok ? EXIT_SUCCESS : EXIT_FAILURE;
     }
 
     if (cmd == "ignore-sigpipe") {
-        // confirm it was ignored
+        // confirm SIGPIPE was ignored
         struct sigaction action;
         sigaction(SIGPIPE, nullptr, &action);
         if (action.sa_handler == SIG_IGN)
diff --git a/tests/auto/corelib/io/qprocess/tst_qprocess.cpp b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
index 7c318f0ca7f..609a6e11138 100644
--- a/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
+++ b/tests/auto/corelib/io/qprocess/tst_qprocess.cpp
@@ -1562,6 +1562,11 @@ void tst_QProcess::unixProcessParameters()
             sigaction(SIGUSR1, &act, &old_sigusr1);
             act.sa_handler = SIG_DFL;
             sigaction(SIGPIPE, &act, &old_sigpipe);
+
+            // and we block SIGUSR2
+            sigset_t *set = &act.sa_mask;               // reuse this sigset_t
+            sigaddset(set, SIGUSR2);
+            sigprocmask(SIG_BLOCK, set, nullptr);
         }
         ~Scope()
         {
@@ -1574,6 +1579,10 @@ void tst_QProcess::unixProcessParameters()
             sigaction(SIGUSR1, &old_sigusr1, nullptr);
             sigaction(SIGPIPE, &old_sigpipe, nullptr);
             devnull = -1;
+
+            sigset_t *set = &old_sigusr1.sa_mask;       // reuse this sigset_t
+            sigaddset(set, SIGUSR2);
+            sigprocmask(SIG_BLOCK, set, nullptr);
         }
     } scope;