diff --git a/toolkit/crashreporter/google-breakpad/src/client/solaris/handler/minidump_generator.cc b/toolkit/crashreporter/google-breakpad/src/client/solaris/handler/minidump_generator.cc
index 7485025fe45f..fcf0dc751d97 100644
--- a/toolkit/crashreporter/google-breakpad/src/client/solaris/handler/minidump_generator.cc
+++ b/toolkit/crashreporter/google-breakpad/src/client/solaris/handler/minidump_generator.cc
@@ -511,7 +511,7 @@ bool ModuleInfoCallback(const ModuleInfo &module_info, void *context) {
   int count;
 
   snprintf(path, sizeof (path), "/proc/self/path/%s", module_info.name);
-  if ((count = readlink(path, buf, PATH_MAX)) < 0)
+  if ((count = readlink(path, buf, PATH_MAX - 1)) < 0)
     return false;
   buf[count] = '\0';