diff --git a/src/common/mythread.h b/src/common/mythread.h
index cd9ae89a..ee8a341d 100644
--- a/src/common/mythread.h
+++ b/src/common/mythread.h
@@ -20,6 +20,9 @@
 		pthread_once(&once_, &func); \
 	} while (0)
 
+#	define mythread_sigmask(how, set, oset) \
+		pthread_sigmask(how, set, oset)
+
 #else
 
 #	define mythread_once(func) \
@@ -31,4 +34,7 @@
 		} \
 	} while (0)
 
+#	define mythread_sigmask(how, set, oset) \
+		sigprocmask(how, set, oset)
+
 #endif
diff --git a/src/xz/main.c b/src/xz/main.c
index 23a2de1f..a3d1101a 100644
--- a/src/xz/main.c
+++ b/src/xz/main.c
@@ -109,7 +109,7 @@ signals_block(void)
 {
 	if (signals_block_count++ == 0) {
 		const int saved_errno = errno;
-		sigprocmask(SIG_BLOCK, &hooked_signals, NULL);
+		mythread_sigmask(SIG_BLOCK, &hooked_signals, NULL);
 		errno = saved_errno;
 	}
 
@@ -124,7 +124,7 @@ signals_unblock(void)
 
 	if (--signals_block_count == 0) {
 		const int saved_errno = errno;
-		sigprocmask(SIG_UNBLOCK, &hooked_signals, NULL);
+		mythread_sigmask(SIG_UNBLOCK, &hooked_signals, NULL);
 		errno = saved_errno;
 	}
 
diff --git a/src/xz/private.h b/src/xz/private.h
index b463a08e..9f0c52cc 100644
--- a/src/xz/private.h
+++ b/src/xz/private.h
@@ -21,6 +21,7 @@
 #define PRIVATE_H
 
 #include "sysdefs.h"
+#include "mythread.h"
 
 #include <sys/types.h>
 #include <sys/stat.h>