diff --git a/server.c b/server.c
index ac6c2fb..2c20e37 100644
--- a/server.c
+++ b/server.c
@@ -409,7 +409,10 @@
 	size_t size;
 	int i;
 
-	size = sizeof(*je) + thread_number * sizeof(char);
+	if (!thread_number)
+		return 0;
+
+	size = sizeof(*je) + thread_number * sizeof(char) + 1;
 	je = malloc(size);
 	memset(je, 0, size);