diff --git a/pkgs/development/r-modules/default.nix b/pkgs/development/r-modules/default.nix
index 00a84bf0e0a4..35822fa78bd4 100644
--- a/pkgs/development/r-modules/default.nix
+++ b/pkgs/development/r-modules/default.nix
@@ -437,6 +437,7 @@ let
     KernSmooth = [ pkgs.libiconv ];
     nlme = [ pkgs.libiconv ];
     Matrix = [ pkgs.libiconv ];
+    mgcv = [ pkgs.libiconv ];
   };
 
   packagesRequireingX = [