diff --git a/required/tools/build.lua b/required/tools/build.lua
index 015407e10..e6d00e747 100644
--- a/required/tools/build.lua
+++ b/required/tools/build.lua
@@ -22,6 +22,7 @@ sourcefiles  = {"*.dtx", "*.ins", "*-????-??-??.sty"}
 checkdeps =
   {
     maindir .. "/base",
+    maindir .. "/required/amsmath",
     maindir .. "/required/graphics"
   }