diff --git a/cpu/native/irq_cpu.c b/cpu/native/irq_cpu.c
index 9e265ba6094c3..ba37efe88e018 100644
--- a/cpu/native/irq_cpu.c
+++ b/cpu/native/irq_cpu.c
@@ -229,7 +229,7 @@ int irq_is_in(void)
 int _native_popsig(void)
 {
     int nread, nleft, i;
-    int sig;
+    int sig = -1;
 
     nleft = sizeof(int);
     i = 0;