diff --git a/scripts/tint_overrides_with_defaults.gni b/scripts/tint_overrides_with_defaults.gni
index 8cfa9ae..ef80770 100644
--- a/scripts/tint_overrides_with_defaults.gni
+++ b/scripts/tint_overrides_with_defaults.gni
@@ -70,6 +70,11 @@
     tint_spirv_headers_dir = "//third_party/spirv-headers/src"
   }
 
+  # Path to libprotobuf-mutator checkout
+  if (!defined(tint_lpm_dir)) {
+    tint_lpm_dir = "//third_party/libprotobuf-mutator"
+  }
+
   if (!defined(tint_build_cmds)) {
     tint_build_cmds = tint_standalone
   }