diff --git a/src/overlays/nix.nix b/src/overlays/nix.nix
new file mode 100644
index 0000000..0f715dc
--- /dev/null
+++ b/src/overlays/nix.nix
@@ -0,0 +1,7 @@
+final: prev:  {
+  nix = prev.nix.overrideAttrs (old: {
+    patches = (old.patches or []) ++ [
+      ./nix/5567-make-installables-expr-context.patch
+    ];
+  });
+}
diff --git a/src/overlays/nix/5567-make-installables-expr-context.patch b/src/overlays/nix/5567-make-installables-expr-context.patch
new file mode 100644
index 0000000..d41d664
--- /dev/null
+++ b/src/overlays/nix/5567-make-installables-expr-context.patch
@@ -0,0 +1,150 @@
+From 519d541fdc71508793ece6e087d2c1a231378558 Mon Sep 17 00:00:00 2001
+From: Skyler Grey <skyler3665@gmail.com>
+Date: Wed, 20 Jul 2022 14:45:45 +0100
+Subject: [PATCH 1/4] Make --expr always include nixpkgs
+
+---
+ src/libcmd/installables.cc | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
+index 59162c4df03..7dc3f7435ee 100644
+--- a/src/libcmd/installables.cc
++++ b/src/libcmd/installables.cc
+@@ -778,8 +778,11 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
+         } else if (file)
+             state->evalFile(lookupFileArg(*state, *file), *vFile);
+         else {
+-            auto e = state->parseExprFromString(*expr, absPath("."));
+-            state->eval(e, *vFile);
++            Strings e = {};
++            e.push_back("with (builtins.getFlake \"nixpkgs\")");
++            e.push_back(*expr);
++            auto parsed = state->parseExprFromString(concatStringsSep(";", e), absPath("."));
++            state->eval(parsed, *vFile);
+         }
+ 
+         for (auto & s : ss) {
+
+From 29b83de5671901e5e8755c17b840139a6f8650db Mon Sep 17 00:00:00 2001
+From: Skyler Grey <skyler3665@gmail.com>
+Date: Wed, 20 Jul 2022 14:46:17 +0100
+Subject: [PATCH 2/4] Stop --expr requiring --impure flag
+
+---
+ src/libcmd/installables.cc | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
+index 7dc3f7435ee..43e759b3e93 100644
+--- a/src/libcmd/installables.cc
++++ b/src/libcmd/installables.cc
+@@ -767,7 +767,7 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
+             throw UsageError("'--file' and '--expr' are exclusive");
+ 
+         // FIXME: backward compatibility hack
+-        if (file) evalSettings.pureEval = false;
++        evalSettings.pureEval = false;
+ 
+         auto state = getEvalState();
+         auto vFile = state->allocValue();
+
+From 9e9d28496a7216a0e2893ac0eb05a8c45d898c95 Mon Sep 17 00:00:00 2001
+From: Skyler Grey <skyler3665@gmail.com>
+Date: Wed, 20 Jul 2022 23:51:16 +0100
+Subject: [PATCH 3/4] Make nix shell take installables as context
+
+---
+ src/libcmd/installables.cc | 46 +++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 45 insertions(+), 1 deletion(-)
+
+diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
+index 43e759b3e93..1abad72e333 100644
+--- a/src/libcmd/installables.cc
++++ b/src/libcmd/installables.cc
+@@ -779,10 +779,54 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
+             state->evalFile(lookupFileArg(*state, *file), *vFile);
+         else {
+             Strings e = {};
+-            e.push_back("with (builtins.getFlake \"nixpkgs\")");
++
++            for (auto & s : ss) {
++                std::exception_ptr ex;
++
++                if (s.find('/') != std::string::npos) {
++                    try {
++                        result.push_back(std::make_shared<InstallableStorePath>(store, store->followLinksToStorePath(s)));
++                        continue;
++                    } catch (BadStorePath &) {
++                    } catch (...) {
++                        if (!ex)
++                            ex = std::current_exception();
++                    }
++                }
++
++                try {
++                    auto [flakeRef, fragment, outputsSpec] = parseFlakeRefWithFragmentAndOutputsSpec(s, absPath("."));
++/*                    result.push_back(std::make_shared<InstallableFlake>(
++                            this,
++                            getEvalState(),
++                            std::move(flakeRef),
++                            fragment,
++                            outputsSpec,
++                            getDefaultFlakeAttrPaths(),
++                            getDefaultFlakeAttrPathPrefixes(),
++                            lockFlags));*/
++                    e.push_back("with (builtins.getFlake \"" + flakeRef.to_string() + "\")" + (fragment != "" ? "." + fragment : ""));
++                    e.push_back("with (builtins.getFlake \"" + flakeRef.to_string() + "\").packages.\"${builtins.currentSystem}\"" + (fragment != "" ? "." + fragment : ""));
++                    e.push_back("with (builtins.getFlake \"" + flakeRef.to_string() + "\").legacyPackages.\"${builtins.currentSystem}\"" + (fragment != "" ? "." + fragment : ""));
++                    continue;
++                } catch (...) {
++                    ex = std::current_exception();
++                }
++
++                std::rethrow_exception(ex);
++            }
++
+             e.push_back(*expr);
+             auto parsed = state->parseExprFromString(concatStringsSep(";", e), absPath("."));
+             state->eval(parsed, *vFile);
++
++            auto [prefix, outputsSpec] = parseOutputsSpec(".");
++            result.push_back(
++                std::make_shared<InstallableAttrPath>(
++                    state, *this, vFile,
++                    prefix == "." ? "" : prefix,
++                    outputsSpec));
++            return result;
+         }
+ 
+         for (auto & s : ss) {
+
+From e3045be11cbac91a5e65ef42e42e320e6689e713 Mon Sep 17 00:00:00 2001
+From: Skyler Grey <skyler3665@gmail.com>
+Date: Wed, 20 Jul 2022 23:56:09 +0100
+Subject: [PATCH 4/4] Update documentation to match nix shell change
+
+---
+ src/nix/nix.md | 9 +++++++--
+ 1 file changed, 7 insertions(+), 2 deletions(-)
+
+diff --git a/src/nix/nix.md b/src/nix/nix.md
+index d48682a9432..b5bee708451 100644
+--- a/src/nix/nix.md
++++ b/src/nix/nix.md
+@@ -139,8 +139,13 @@ the Nix store. Here are the recognised types of installables:
+ * **Nix expressions**: `--expr '(import <nixpkgs> {}).hello.overrideDerivation (prev: { name = "my-hello"; })'`.
+ 
+   When the `--expr` option is given, all installables are interpreted
+-  as Nix expressions. You may need to specify `--impure` if the
+-  expression references impure inputs (such as `<nixpkgs>`).
++  as context for the expression. For example, the following is valid:
++
++  ```console
++  # nix shell nixpkgs#python3 --expr 'withPackages(pyPkgs: with pyPkgs; [ numpy ])'
++  ```
++
++  Using `--expr` implies `--impure`.
+ 
+ For most commands, if no installable is specified, the default is `.`,
+ i.e. Nix will operate on the default flake output attribute of the