diff --git a/lib/log.c b/lib/log.c
index 86b54eb..9d56680 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -232,7 +232,8 @@
     void *array[20];
     int size;
 
-    size = backtrace(array,sizeof(array)/sizeof(array[0]));
+    if ((size = backtrace(array,sizeof(array)/sizeof(array[0]))) <= 0)
+      return;
     s = buf;
     s = str_append(LOC,"Backtrace for ");
     s = num_append(LOC,size);