1 files changed, 3 insertions, 0 deletions
diff --git a/signal.c b/signal.c
index 4755f590f0..f34e78d588 100644
--- a/signal.c
+++ b/signal.c
@@ -448,6 +448,9 @@ trap(arg)
     if (sig == SIGVTALRM) {
 	ArgError("SIGVTALRM reserved for Thread; cannot set handler");
     }
+    if (sig == SIGALRM) {
+	ArgError("SIGALRM reserved for Thread; cannot set handler");
+    }
 #endif
     if (func == SIG_DFL) {
 	switch (sig) {