diff --git a/flutter/build_fdroid.sh b/flutter/build_fdroid.sh
index 1821c529afb5..40fe3c3c3513 100755
--- a/flutter/build_fdroid.sh
+++ b/flutter/build_fdroid.sh
@@ -237,7 +237,9 @@ prebuild)
 
 	# Install rust bridge generator
 
-	cargo install cargo-expand
+	cargo install \
+		cargo-expand \
+		--locked
 	cargo install flutter_rust_bridge_codegen \
 		--version "${FLUTTER_RUST_BRIDGE_VERSION}" \
 		--features "uuid" \