diff --git a/pkgs/stdenv/adapters.nix b/pkgs/stdenv/adapters.nix
index 47486398013..c4f8b6db8f2 100644
--- a/pkgs/stdenv/adapters.nix
+++ b/pkgs/stdenv/adapters.nix
@@ -153,7 +153,7 @@ rec {
                     # any library needed to link the program dynamically at
                     # loader time. ld(1) explains it.
                     buildInputs = [];
-                    propagatedBuildInputs = propagatedBuildInputsDrvs +
+                    propagatedBuildInputs = propagatedBuildInputsDrvs ++
                       buildInputsDrvs;
                     propagatedBuildNativeInputs = propagatedBuildNativeInputsDrvs;