diff --git a/lang/reader.rkt b/lang/reader.rkt
index ad2d914..914cb31 100644
--- a/lang/reader.rkt
+++ b/lang/reader.rkt
@@ -1,6 +1,7 @@
 #lang racket/base
 (require (only-in scribble/reader make-at-reader)
-         (only-in (planet mb/pollen/world) POLLEN_EXPRESSION_DELIMITER))
+         (only-in "../world.rkt" POLLEN_EXPRESSION_DELIMITER)
+         (only-in "../pollen-file-tools.rkt" preproc-source?))
 
 (provide (rename-out [mb-read read]
                      [mb-read-syntax read-syntax])
@@ -20,8 +21,13 @@
   `(module pollen-lang-module (planet mb/pollen) 
      ,@i))
 
-(define (mb-read-syntax name p)
-  (define i (read-inner name p))
+
+(define (mb-read-syntax path-string p)
+  (define i (read-inner path-string p))
   (datum->syntax i 
-                 (make-output-datum i)
+                 ;; select pollen dialect based on file type
+                 `(module pollen-lang-module ,(if (preproc-source? path-string)
+                                                  '(planet mb/pollen/main-preproc)
+                                                  '(planet mb/pollen/main))
+                    ,@i)
                  i))
diff --git a/main-pre.rkt b/main-preproc.rkt
similarity index 100%
rename from main-pre.rkt
rename to main-preproc.rkt
diff --git a/pre/lang/reader.rkt b/pre/lang/reader.rkt
deleted file mode 100644
index 0521318..0000000
--- a/pre/lang/reader.rkt
+++ /dev/null
@@ -1,27 +0,0 @@
-#lang racket/base
-(require (only-in scribble/reader make-at-reader)
-         (only-in (planet mb/pollen/world) POLLEN_EXPRESSION_DELIMITER))
-
-(provide (rename-out [mb-read read]
-                     [mb-read-syntax read-syntax])
-         read-inner
-         )
-
-(define read-inner
-  (make-at-reader #:command-char POLLEN_EXPRESSION_DELIMITER
-                  #:syntax? #t
-                  #:inside? #t))
-
-(define (mb-read p)
-  (syntax->datum
-   (mb-read-syntax (object-name p) p)))
-
-(define (make-output-datum i)
-  `(module lang-module (planet mb/pollen/main-pre) 
-     ,@i))
-
-(define (mb-read-syntax name p)
-  (define i (read-inner name p))
-  (datum->syntax i 
-                 (make-output-datum i)
-                 i))