diff --git a/src/Makefile b/src/Makefile
index 3f84d24..a75c080 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -23,7 +23,7 @@ manifests: $(manifests)
 ../build/firmware/armv7-none-eabihf/release/runtime: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(manifests) $(shell find . -type f -not -name Cargo.toml -print)
 	cd runtime && \
 	XBUILD_SYSROOT_PATH=`pwd`/../../build/sysroot \
-	cargo xbuild --release \
+	cargo xbuild --release --locked \
 		--target-dir ../../build/firmware \
 		--no-default-features --features=target_$(TARGET)
 
@@ -33,7 +33,7 @@ manifests: $(manifests)
 ../build/firmware/armv7-none-eabihf/release/satman: ../build/pl.rs ../build/rustc-cfg ../build/mem.rs $(manifests) $(shell find . -type f -not -name Cargo.toml -print)
 	cd satman && \
 	XBUILD_SYSROOT_PATH=`pwd`/../../build/sysroot \
-	cargo xbuild --release \
+	cargo xbuild --release --locked \
 		--target-dir ../../build/firmware \
 		--no-default-features --features=target_$(TARGET)