diff --git a/libisoburn/trunk/test/compare_file.c b/libisoburn/trunk/test/compare_file.c
index 38620d98..4f5bb04f 100644
--- a/libisoburn/trunk/test/compare_file.c
+++ b/libisoburn/trunk/test/compare_file.c
@@ -111,10 +111,12 @@ int Compare_2_files(char *adr1, char *adr2, char *adrc, int flag)
  }
  strcpy(a, Ftypetxt(s1.st_mode, 1));
  strcat(a, " ");
- if(adrc[0])
-   strcat(a, adrc);
- else
+ if(adrc[0]) {
+   if(strlen(a) + strlen(adrc) < 4096)
+     strcat(a, adrc);
+ } else {
    strcat(a, ".");
+ }
 
  ret= lstat(adr2, &s2);
  if(ret==-1) {