diff --git a/checkin_notes b/checkin_notes
index 9ae42ff771..46f5f87685 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -5928,3 +5928,9 @@ Rom    19 June 2009
     clientgui/
         AccountManagerPropertiesPage.cpp
         ProjectPropertiesPage.cpp
+
+Rom    19 June 2009
+    - Mac Install: Fix an off by one error reported during a security audit
+    
+    mac_install/
+        CustomInstall.cpp
diff --git a/mac_installer/CustomInstall.cpp b/mac_installer/CustomInstall.cpp
index c0d3c0a64f..c332545df2 100644
--- a/mac_installer/CustomInstall.cpp
+++ b/mac_installer/CustomInstall.cpp
@@ -89,7 +89,7 @@ int main(int argc, char *argv[])
         show_message((StringPtr)"\pPath to application is too long.");
         return 0;
     }
-    strncpy(path, argv[0], sizeof(path));   // Path to this application.
+    strncpy(path, argv[0], sizeof(path)-1);   // Path to this application.
     p = strstr(path, "/Contents/MacOS/");
     *p = '\0';
     p = strrchr(path, '/');