diff --git a/nixos/modules/programs/command-not-found/command-not-found.nix b/nixos/modules/programs/command-not-found/command-not-found.nix
index bead2dcdcf9..9524d91ea3b 100644
--- a/nixos/modules/programs/command-not-found/command-not-found.nix
+++ b/nixos/modules/programs/command-not-found/command-not-found.nix
@@ -57,9 +57,9 @@ in
           if [ $? = 126 ]; then
             "$@"
           fi
-	else
+        else
           # Indicate than there was an error so ZSH falls back to its default handler
-	  return 127
+          return 127
         fi
       }
     '';
diff --git a/nixos/modules/programs/command-not-found/command-not-found.pl b/nixos/modules/programs/command-not-found/command-not-found.pl
index 621b79d1654..b233d973a4a 100644
--- a/nixos/modules/programs/command-not-found/command-not-found.pl
+++ b/nixos/modules/programs/command-not-found/command-not-found.pl
@@ -30,11 +30,11 @@ The program ‘$program’ is currently not installed. It is provided by
 the package ‘$package’, which I will now install for you.
 EOF
         ;
-        exit 126 if system("nix-env", "-iA", $package) == 0;
+        exit 126 if system("nix-env", "-iA", "nixos.$package") == 0;
     } else {
         print STDERR <<EOF;
 The program ‘$program’ is currently not installed. You can install it by typing:
-  nix-env -iA $package
+  nix-env -iA nixos.$package
 EOF
     }
 } else {
@@ -42,7 +42,7 @@ EOF
 The program ‘$program’ is currently not installed. It is provided by
 several packages. You can install it by typing one of the following:
 EOF
-    print STDERR "  nix-env -iA $_->{package}\n" foreach @$res;
+    print STDERR "  nix-env -iA nixos.$_->{package}\n" foreach @$res;
 }
 
 exit 127;