diff --git a/Project.toml b/Project.toml
index 82ce0637..03946219 100644
--- a/Project.toml
+++ b/Project.toml
@@ -19,7 +19,7 @@ Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 
 [extensions]
 DataInterpolationsChainRulesCoreExt = "ChainRulesCore"
-DataInterpolationsOptimExt = "Optim"
+DataInterpolationsOptimExt = ["ForwardDiff", "Optim"]
 DataInterpolationsRegularizationToolsExt = "RegularizationTools"
 DataInterpolationsSymbolicsExt = "Symbolics"