diff --git a/package/pkg-cargo.mk b/package/pkg-cargo.mk
index e74a8358bc..66bea513e0 100644
--- a/package/pkg-cargo.mk
+++ b/package/pkg-cargo.mk
@@ -69,7 +69,7 @@ define inner-cargo-package
 $(2)_DOWNLOAD_DEPENDENCIES += host-rustc
 
 $(2)_DOWNLOAD_POST_PROCESS = cargo
-$(2)_DL_ENV = CARGO_HOME=$$(HOST_DIR)/share/cargo
+$(2)_DL_ENV += CARGO_HOME=$$(HOST_DIR)/share/cargo
 
 # Due to vendoring, it is pretty likely that not all licenses are
 # listed in <pkg>_LICENSE.