diff --git a/REQUIRE b/REQUIRE
index 4ec734b..db8c277 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -2,6 +2,7 @@ julia 0.6
 Mimi
 NLopt
 ForwardDiff 0.2.5
+DiffBase
 MathProgBase
 DataFrames
 Clp