diff --git a/ego/Cargo.toml b/ego/Cargo.toml
index 8a0f044c..a2b32245 100644
--- a/ego/Cargo.toml
+++ b/ego/Cargo.toml
@@ -32,7 +32,7 @@ ndarray = { version = "0.15", features = ["rayon", "approx"] }
 ndarray-linalg = { version = "0.15", optional = true }
 ndarray-stats = "0.5"
 ndarray-rand = "0.14"
-ndarray-npy = "0.8"
+ndarray-npy = "0.9"
 rayon = "1"
 
 cobyla = { version = "0.6" }
diff --git a/gp/Cargo.toml b/gp/Cargo.toml
index 71364bce..f0b89c5f 100644
--- a/gp/Cargo.toml
+++ b/gp/Cargo.toml
@@ -29,7 +29,7 @@ ndarray-linalg = { version = "0.15", optional = true }
 ndarray-stats = "0.5"
 ndarray_einsum_beta = "0.7"
 ndarray-rand = "0.14"
-ndarray-npy = "0.8"
+ndarray-npy = "0.9"
 nlopt = { version = "0.7.0", optional = true }
 cobyla = { version = "0.6" }
 rand_xoshiro = "0.6"
diff --git a/moe/Cargo.toml b/moe/Cargo.toml
index ac857464..4c1637e1 100644
--- a/moe/Cargo.toml
+++ b/moe/Cargo.toml
@@ -41,7 +41,7 @@ ndarray = { version = "0.15", features = ["rayon", "approx"] }
 ndarray-linalg = { version = "0.15", optional = true }
 ndarray-stats = "0.5"
 ndarray-rand = "0.14"
-ndarray-npy = "0.8"
+ndarray-npy = "0.9"
 rand_xoshiro = "0.6"
 paste = "1.0"
 bitflags = { version = "2.4.1", features = ["serde"] }
@@ -56,7 +56,7 @@ typetag = { version = "0.2", optional = true }
 [dev-dependencies]
 criterion = "0.5"
 approx = "0.4"
-ndarray-npy = "0.8"
+ndarray-npy = "0.9"
 ndarray-csv = "0.5"
 csv = "1.1"
 argmin_testfunctions = "0.2"