diff --git a/src/main.c b/src/main.c
index 36143a2..cecc91d 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,6 +32,8 @@
 #include <sys/types.h>
 #include <fcntl.h>
 #include <locale.h>
+#include <signal.h>
+#include <pthread.h>
 
 
 /* Xlocale.h and locale.h are the same if X_LOCALE is undefind in wconfig.h,
@@ -617,6 +619,16 @@ static int real_main(int argc, char **argv)
 {
 	int i;
 
+	/* Block SIGUSR2 early so all threads (including library threads like
+	 * pango's fontconfig thread) inherit the blocked mask.  The signalfd
+	 * in the Wayland event loop will be the sole recipient. */
+	{
+		sigset_t ss;
+		sigemptyset(&ss);
+		sigaddset(&ss, SIGUSR2);
+		pthread_sigmask(SIG_BLOCK, &ss, NULL);
+	}
+
 	setlocale(LC_ALL, "");
 	wsetabort(wAbort);