diff --git a/pkgs/development/interpreters/tcl/generic.nix b/pkgs/development/interpreters/tcl/generic.nix
index 535ac2bd30d0..fcc9966ef069 100644
--- a/pkgs/development/interpreters/tcl/generic.nix
+++ b/pkgs/development/interpreters/tcl/generic.nix
@@ -225,6 +225,7 @@ stdenv.mkDerivation (finalAttrs: {
           name = "tcl-requires-check-hook";
           substitutions = {
             tcl_hook = ./tcl-requires-check-hook.tcl;
+            tclsh = lib.getExe finalAttrs.finalPackage;
           };
           meta = {
             inherit (finalAttrs.meta) maintainers platforms;
diff --git a/pkgs/development/interpreters/tcl/tcl-requires-check-hook.sh b/pkgs/development/interpreters/tcl/tcl-requires-check-hook.sh
index 6e3066d03b48..9600416c55dd 100644
--- a/pkgs/development/interpreters/tcl/tcl-requires-check-hook.sh
+++ b/pkgs/development/interpreters/tcl/tcl-requires-check-hook.sh
@@ -7,7 +7,7 @@ tclRequiresCheckPhase () {
     if [ -n "$tclRequiresCheck" ]; then
         export TCLLIBPATH="$out/lib $TCLLIBPATH" # Redundant if tcl-package-hook is also used
         # FIXME: For some reason the output gets swallowed unless we pipe it through cat‽
-        tclsh @tcl_hook@ 2>&1 | cat
+        @tclsh@ @tcl_hook@ 2>&1 | cat
     fi
 }
 
diff --git a/pkgs/development/tcl-modules/by-name/rl/rl_json/package.nix b/pkgs/development/tcl-modules/by-name/rl/rl_json/package.nix
index 67a9717397ac..f1a12aaefb51 100644
--- a/pkgs/development/tcl-modules/by-name/rl/rl_json/package.nix
+++ b/pkgs/development/tcl-modules/by-name/rl/rl_json/package.nix
@@ -27,6 +27,7 @@ stdenv.mkDerivation (finalAttrs: {
   nativeBuildInputs = [
     autoreconfHook
     tcl.tclPackageHook
+    tcl.tclRequiresCheckHook
     pandoc
   ];
 
@@ -39,6 +40,8 @@ stdenv.mkDerivation (finalAttrs: {
 
   doCheck = true;
 
+  tclRequiresCheck = [ "rl_json" ];
+
   meta = {
     homepage = "https://github.com/RubyLane/rl_json";
     description = "Tcl extension for fast json manipulation";