diff --git a/pkgs/build-support/bintools-wrapper/default.nix b/pkgs/build-support/bintools-wrapper/default.nix
index 9f5395b635e..4a56f00db49 100644
--- a/pkgs/build-support/bintools-wrapper/default.nix
+++ b/pkgs/build-support/bintools-wrapper/default.nix
@@ -199,11 +199,7 @@ stdenv.mkDerivation {
   ];
 
   postFixup =
-    ''
-      set -u
-    ''
-
-    + optionalString (libc != null) (''
+    optionalString (libc != null) (''
       ##
       ## General libc support
       ##
diff --git a/pkgs/build-support/bintools-wrapper/setup-hook.sh b/pkgs/build-support/bintools-wrapper/setup-hook.sh
index 2e15fa95c79..a714bd151c9 100644
--- a/pkgs/build-support/bintools-wrapper/setup-hook.sh
+++ b/pkgs/build-support/bintools-wrapper/setup-hook.sh
@@ -2,8 +2,6 @@
 #
 # See comments in cc-wrapper's setup hook. This works exactly the same way.
 
-set -u
-
 # Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
 # native compile.
 #
@@ -73,4 +71,3 @@ export NIX_HARDENING_ENABLE
 
 # No local scope in sourced file
 unset -v role_pre role_post cmd upper_case
-set +u
diff --git a/pkgs/build-support/cc-wrapper/default.nix b/pkgs/build-support/cc-wrapper/default.nix
index cf2d38cd997..d6037552ef6 100644
--- a/pkgs/build-support/cc-wrapper/default.nix
+++ b/pkgs/build-support/cc-wrapper/default.nix
@@ -134,8 +134,6 @@ stdenv.mkDerivation {
 
   installPhase =
     ''
-      set -u
-
       mkdir -p $out/bin $out/nix-support
 
       wrap() {
@@ -224,8 +222,6 @@ stdenv.mkDerivation {
 
   postFixup =
     ''
-      set -u
-
       # Backwards compatability for packages expecting this file, e.g. with
       # `$NIX_CC/nix-support/dynamic-linker`.
       #
diff --git a/pkgs/build-support/cc-wrapper/setup-hook.sh b/pkgs/build-support/cc-wrapper/setup-hook.sh
index 211b5063291..5b13f268309 100644
--- a/pkgs/build-support/cc-wrapper/setup-hook.sh
+++ b/pkgs/build-support/cc-wrapper/setup-hook.sh
@@ -54,8 +54,6 @@
 # For more details, read the individual files where the mechanisms used to
 # accomplish this will be individually documented.
 
-set -u
-
 # Skip setup hook if we're neither a build-time dep, nor, temporarily, doing a
 # native compile.
 #
@@ -120,4 +118,3 @@ export NIX_HARDENING_ENABLE
 
 # No local scope in sourced file
 unset -v role_pre role_post
-set +u