diff --git a/flatdata-rs/lib/Cargo.toml b/flatdata-rs/lib/Cargo.toml
index 636f73c4..ff233170 100644
--- a/flatdata-rs/lib/Cargo.toml
+++ b/flatdata-rs/lib/Cargo.toml
@@ -12,7 +12,7 @@ edition = "2018"
 
 [dependencies]
 diff = "0.1.11"
-memmap2 = "0.5.7"
+memmap2 = "0.9.4"
 tar = { version = "0.4.38", optional = true }
 walkdir = "2.2.9"