diff --git a/flake.nix b/flake.nix
index 806ed45de..f4fae2a00 100644
--- a/flake.nix
+++ b/flake.nix
@@ -667,6 +667,9 @@
               PATH=$prefix/bin:$PATH
               unset PYTHONPATH
               export MANPATH=$out/share/man:$MANPATH
+
+              # Make bash completion work.
+              XDG_DATA_DIRS+=:$out/share
             '';
         });
 
diff --git a/misc/bash/completion.sh b/misc/bash/completion.sh
index bea2a40bc..0af90d8c1 100644
--- a/misc/bash/completion.sh
+++ b/misc/bash/completion.sh
@@ -13,7 +13,7 @@ function _complete_nix {
         else
             COMPREPLY+=("$completion")
         fi
-    done < <(NIX_GET_COMPLETIONS=$cword "${words[@]}")
+    done < <(NIX_GET_COMPLETIONS=$cword "${words[@]/#\~/$HOME}")
     __ltrim_colon_completions "$cur"
 }