diff --git a/test/Project.toml b/test/Project.toml
index 086a88d..18301ee 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -3,6 +3,7 @@ ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"
 ChainRulesTestUtils = "cdddcdb0-9152-4a09-a978-84456f9df70a"
 Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
+FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"
 FiniteDifferences = "26cc04aa-876d-5657-8c51-4c34ba976000"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 LazyArrays = "5078a376-72f3-5289-bfd5-ec5146d43c02"
@@ -21,6 +22,7 @@ ChainRulesCore = "1"
 ChainRulesTestUtils = "1.9.2"
 Combinatorics = "1.0.2"
 Distributions = "0.25.15"
+FillArrays = "=1.0.0"
 FiniteDifferences = "0.11.3, 0.12"
 ForwardDiff = "0.10.12"
 LazyArrays = "1"