diff --git a/pkgs/build-support/bintools-wrapper/add-hardening.sh b/pkgs/build-support/bintools-wrapper/add-hardening.sh
index a15be821659f..b7180870860a 100644
--- a/pkgs/build-support/bintools-wrapper/add-hardening.sh
+++ b/pkgs/build-support/bintools-wrapper/add-hardening.sh
@@ -11,7 +11,7 @@ done
 
 # Remove unsupported flags.
 for flag in @hardening_unsupported_flags@; do
-  unset -v hardeningEnableMap["$flag"]
+  unset -v "hardeningEnableMap[$flag]"
 done
 
 if (( "${NIX_DEBUG:-0}" >= 1 )); then
diff --git a/pkgs/build-support/cc-wrapper/add-hardening.sh b/pkgs/build-support/cc-wrapper/add-hardening.sh
index 026e48671447..fc40fe7408b6 100644
--- a/pkgs/build-support/cc-wrapper/add-hardening.sh
+++ b/pkgs/build-support/cc-wrapper/add-hardening.sh
@@ -11,7 +11,7 @@ done
 
 # Remove unsupported flags.
 for flag in @hardening_unsupported_flags@; do
-  unset -v hardeningEnableMap["$flag"]
+  unset -v "hardeningEnableMap[$flag]"
 done
 
 if (( "${NIX_DEBUG:-0}" >= 1 )); then