diff --git a/material-ui/index.d.ts b/material-ui/index.d.ts
index a2661455f8..c399116482 100644
--- a/material-ui/index.d.ts
+++ b/material-ui/index.d.ts
@@ -130,6 +130,7 @@ declare namespace __MaterialUI {
             accent2Color?: string;
             accent3Color?: string;
             textColor?: string;
+            secondaryTextColor?: string;
             alternateTextColor?: string;
             canvasColor?: string;
             borderColor?: string;