diff --git a/Cargo.toml b/Cargo.toml
index de6ece4..e6bafcb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -57,6 +57,7 @@ serde_json = "1"
 streaming-stats = "0.2"
 quantiles = "0.7"
 proptest = "=1.0"
+byteorder = "=1.4" # MSRV 1.56, required by proptest
 
 [package.metadata.docs.rs]
 # Enable certain features when building docs for docs.rs