diff --git a/src/stan/lang/ast/scope.hpp b/src/stan/lang/ast/scope.hpp
index 4878dc88238..82b8afd4ea5 100644
--- a/src/stan/lang/ast/scope.hpp
+++ b/src/stan/lang/ast/scope.hpp
@@ -66,9 +66,10 @@ namespace stan {
       bool is_local() const;
 
       /**
-       * Flags local scopes which permit parameter variables,
-       * i.e., program block can't be transformed data or
-       * generated quantities program blocks.
+       * Flags local scopes which permit parameter variables.
+       * Allows local blocks in functions, transfromed parameter,
+       * and model blocks; disallows local blocks in transformed data
+       * and generated quantities program blocks.
        *
        * @return true for local parameter origin block types
        */
diff --git a/src/stan/lang/ast/scope_def.hpp b/src/stan/lang/ast/scope_def.hpp
index 0d12da44879..95364cc64b6 100644
--- a/src/stan/lang/ast/scope_def.hpp
+++ b/src/stan/lang/ast/scope_def.hpp
@@ -26,9 +26,9 @@ namespace stan {
     }
 
     bool scope::local_allows_var() const {
-      return is_local_ &&
-        !(program_block_ == transformed_data_origin
-          || program_block_ == derived_origin);
+      return is_local_
+        && program_block_ != transformed_data_origin
+        && program_block_ != derived_origin;
     }
 
     bool scope::par_or_tpar() const {