diff --git a/rust/flatbuffers/Cargo.toml b/rust/flatbuffers/Cargo.toml
index 02a268ea6..e8cefbd28 100644
--- a/rust/flatbuffers/Cargo.toml
+++ b/rust/flatbuffers/Cargo.toml
@@ -9,6 +9,7 @@ homepage = "https://google.github.io/flatbuffers/"
 repository = "https://github.com/google/flatbuffers"
 keywords = ["flatbuffers", "serialization", "zero-copy"]
 categories = ["encoding", "data-structures", "memory-management"]
+rust = "1.51"
 
 [dependencies]
 smallvec = "1.6.1"