diff --git a/pkgs/top-level/config.nix b/pkgs/top-level/config.nix
index f2066315efb5..de13c0a29993 100644
--- a/pkgs/top-level/config.nix
+++ b/pkgs/top-level/config.nix
@@ -58,6 +58,34 @@ let
       internal = true;
     };
 
+    attrPathsDisallowedForInternalUse = mkOption {
+      type = types.listOf (
+        types.submodule {
+          options.attrPath = lib.mkOption {
+            type = types.listOf types.str;
+            description = ''
+              Attribute path to disallow.
+            '';
+          };
+          options.reason = lib.mkOption {
+            type = types.nullOr types.str;
+            default = null;
+            example = /* because */ "it's dangerous.";
+            description = ''
+              Reason for it being disallowed.
+            '';
+          };
+        }
+      );
+      internal = true;
+      default = [ ];
+      description = ''
+        List of attribute paths that may not be used by other packages in Nixpkgs.
+
+        Should usually only be defined by Nixpkgs CI.
+      '';
+    };
+
     # Config options
 
     warnUndeclaredOptions = mkOption {
diff --git a/pkgs/top-level/default.nix b/pkgs/top-level/default.nix
index 443496f650fb..4d44abadd961 100644
--- a/pkgs/top-level/default.nix
+++ b/pkgs/top-level/default.nix
@@ -214,7 +214,28 @@ let
       ;
   };
 
-  pkgs = boot stages;
+  fixedPoint = boot stages;
+
+  pkgs =
+    if config.attrPathsDisallowedForInternalUse == [ ] then
+      fixedPoint
+    else
+      # See ./stage.nix, which replaced config.attrPathsDisallowedForInternalUse with aborts.
+      # We replace these attribute paths with their original derivations again,
+      # because CI would just error out from the aborting attributes themselves.
+      # Internally all packages still see the aborting attributes if used as dependencies,
+      # because we do this here after the fixed-point is calculated.
+      # Note that we don't want to remove the attributes entirely like what aliases.nix does,
+      # because unlike aliases, CI still needs to check the packages to evaluate at all,
+      # which it wouldn't if they're removed entirely.
+      lib.updateManyAttrsByPath
+        (map (attrs: {
+          path = attrs.attrPath;
+          update =
+            _:
+            lib.getAttrFromPath attrs.attrPath fixedPoint.__internalBeforeInternallyDisallowedAttrPathsOverlay;
+        }) config.attrPathsDisallowedForInternalUse)
+        (removeAttrs fixedPoint [ "__internalBeforeInternallyDisallowedAttrPathsOverlay" ]);
 
 in
 checked pkgs
diff --git a/pkgs/top-level/stage.nix b/pkgs/top-level/stage.nix
index 4b0abd0361c6..35929783e7c9 100644
--- a/pkgs/top-level/stage.nix
+++ b/pkgs/top-level/stage.nix
@@ -309,6 +309,31 @@ let
     };
   };
 
+  # Replaces the attributes in config.attrPathsDisallowedForInternalUse with aborts.
+  # Not throws because those would be ignored by nix-env, which is what CI uses to evaluate everything
+  # See also ./default.nix, where these attributes are added back again so they're still checked by CI
+  internallyDisallowedAttrPathsOverlay =
+    final: prev:
+    if config.attrPathsDisallowedForInternalUse == [ ] then
+      { }
+    else
+      {
+        # So that ./default.nix can add them back again outside the fixed point
+        # Don't use this in packages!
+        __internalBeforeInternallyDisallowedAttrPathsOverlay = prev;
+      }
+      // lib.updateManyAttrsByPath (map (
+        { attrPath, reason }:
+        {
+          path = attrPath;
+          update =
+            _:
+            abort "${lib.concatStringsSep "." attrPath} is disallowed from being used within Nixpkgs${
+              lib.optionalString (reason != null) ", because ${reason}"
+            }";
+        }
+      ) config.attrPathsDisallowedForInternalUse) prev;
+
   # The complete chain of package set builders, applied from top to bottom.
   # stdenvOverlays must be last as it brings package forward from the
   # previous bootstrapping phases which have already been overlaid.
@@ -324,6 +349,7 @@ let
       aliases
       variants
       configOverrides
+      internallyDisallowedAttrPathsOverlay
     ]
     ++ overlays
     ++ [