diff --git a/configure.ac b/configure.ac
index 215dd64fe..23c0ac285 100644
--- a/configure.ac
+++ b/configure.ac
@@ -159,7 +159,8 @@ dnl Checks for library functions.
 AC_CHECK_FUNCS([backtrace geteuid getuid issetugid getresuid \
 	getdtablesize getifaddrs getpeereid getpeerucred getprogname getzoneid \
 	mmap posix_fallocate seteuid shmctl64 strncasecmp vasprintf vsnprintf \
-	walkcontext setitimer poll epoll_create1 mkostemp memfd_create])
+	walkcontext setitimer poll epoll_create1 mkostemp memfd_create \
+	sigprocmask])
 AC_CONFIG_LIBOBJ_DIR([os])
 AC_REPLACE_FUNCS([reallocarray strcasecmp strcasestr strlcat strlcpy strndup\
 	timingsafe_memcmp])
diff --git a/include/dix-config.h.in b/include/dix-config.h.in
index 9eb1a924e..b463a17f3 100644
--- a/include/dix-config.h.in
+++ b/include/dix-config.h.in
@@ -512,4 +512,7 @@
 /* Have <sys/sysmacros.h> header */
 #undef HAVE_SYS_SYSMACROS_H
 
+/* Have sigprocmask */
+#undef HAVE_SIGPROCMASK
+
 #endif /* _DIX_CONFIG_H_ */
diff --git a/include/meson.build b/include/meson.build
index 527025b24..2c1b49e06 100644
--- a/include/meson.build
+++ b/include/meson.build
@@ -155,6 +155,7 @@ conf_data.set('HAVE_SETEUID', cc.has_function('seteuid'))
 conf_data.set('HAVE_SETITIMER', cc.has_function('setitimer'))
 conf_data.set('HAVE_SHMCTL64', cc.has_function('shmctl64'))
 conf_data.set('HAVE_SIGACTION', cc.has_function('sigaction'))
+conf_data.set('HAVE_SIGPROCMASK', cc.has_function('sigprocmask'))
 conf_data.set('HAVE_STRCASECMP', cc.has_function('strcasecmp'))
 conf_data.set('HAVE_STRCASESTR', cc.has_function('strcasestr'))
 conf_data.set('HAVE_STRLCAT', cc.has_function('strlcat', dependencies: libbsd_dep))
diff --git a/os/inputthread.c b/os/inputthread.c
index e6694afda..361d96efa 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -558,7 +558,11 @@ extern int InputThreadUnregisterDev(int fd)
 
 int xthread_sigmask(int how, const sigset_t *set, sigset_t *oldset)
 {
+#ifdef HAVE_SIGPROCMASK
     return sigprocmask(how, set, oldset);
+#else
+    return 0;
+#endif
 }
 
 #endif
diff --git a/os/utils.c b/os/utils.c
index f04bf8045..d1cd07ccc 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1281,7 +1281,7 @@ SmartScheduleInit(void)
 #endif
 }
 
-#ifdef SIG_BLOCK
+#ifdef HAVE_SIGPROCMASK
 static sigset_t PreviousSignalMask;
 static int BlockedSignalCount;
 #endif
@@ -1289,7 +1289,7 @@ static int BlockedSignalCount;
 void
 OsBlockSignals(void)
 {
-#ifdef SIG_BLOCK
+#ifdef HAVE_SIGPROCMASK
     if (BlockedSignalCount++ == 0) {
         sigset_t set;
 
@@ -1311,7 +1311,7 @@ OsBlockSignals(void)
 void
 OsReleaseSignals(void)
 {
-#ifdef SIG_BLOCK
+#ifdef HAVE_SIGPROCMASK
     if (--BlockedSignalCount == 0) {
         xthread_sigmask(SIG_SETMASK, &PreviousSignalMask, 0);
     }
@@ -1321,7 +1321,7 @@ OsReleaseSignals(void)
 void
 OsResetSignals(void)
 {
-#ifdef SIG_BLOCK
+#ifdef HAVE_SIGPROCMASK
     while (BlockedSignalCount > 0)
         OsReleaseSignals();
     input_force_unlock();