diff --git a/krebs/4lib/default.nix b/krebs/4lib/default.nix
index b67585335..8b587dfb2 100644
--- a/krebs/4lib/default.nix
+++ b/krebs/4lib/default.nix
@@ -14,5 +14,6 @@ builtins // lib // rec {
 
   dns = import ./dns.nix { inherit lib; };
   listset = import ./listset.nix { inherit lib; };
+  shell = import ./shell.nix { inherit lib; };
   tree = import ./tree.nix { inherit lib; };
 }
diff --git a/krebs/4lib/shell.nix b/krebs/4lib/shell.nix
new file mode 100644
index 000000000..48b220f87
--- /dev/null
+++ b/krebs/4lib/shell.nix
@@ -0,0 +1,15 @@
+{ lib, ... }:
+
+with builtins;
+with lib;
+
+rec {
+  escape =
+    let
+      isSafeChar = c: match "[-./0-9_a-zA-Z]" c != null;
+    in
+    stringAsChars (c:
+      if isSafeChar c then c
+      else if c == "\n" then "'\n'"
+      else "\\${c}");
+}
diff --git a/tv/4lib/default.nix b/tv/4lib/default.nix
index 352689af4..106535ba2 100644
--- a/tv/4lib/default.nix
+++ b/tv/4lib/default.nix
@@ -16,12 +16,5 @@ krebs // rec {
   # "7.4.335" -> "74"
   majmin = with lib; x : concatStrings (take 2 (splitString "." x));
 
-  shell-escape =
-    let
-      isSafeChar = c: match "[-./0-9_a-zA-Z]" c != null;
-    in
-    stringAsChars (c:
-      if isSafeChar c then c
-      else if c == "\n" then "'\n'"
-      else "\\${c}");
+  shell-escape = krebs.shell.escape;
 }