diff --git a/library.scm b/library.scm
index fb85c86..1a5d2fa 100644
--- a/library.scm
+++ b/library.scm
@@ -3713,6 +3713,7 @@ EOF
         "Version " ##sys#build-version
         (if ##sys#build-branch (string-append " (" ##sys#build-branch ")") "")
         (if ##sys#build-id (string-append " (rev " ##sys#build-id ")") "")
+#+debugbuild " ** DEBUGBUILD ** "
         "\n"
         (get-config)
         (if (zero? (##sys#size spec))
@@ -3761,6 +3762,9 @@ EOF
 (when (##sys#fudge 39) (set! ##sys#features (cons #:cross-chicken ##sys#features)))
 (when (##sys#fudge 3) (set! ##sys#features (cons #:64bit ##sys#features)))
 
+#+debugbuild
+(set! ##sys#features (cons #:debugbuild ##sys#features))
+
 (set! ##sys#features
   (let ((major (##sys#string-append "chicken-" (##sys#number->string (##sys#fudge 41)))))
     (cons (##sys#->feature-id major)




]$ ./csi

CHICKEN
(c) 2008-2014, The CHICKEN Team
(c) 2000-2007, Felix L. Winkelmann
Version 4.9.1 (rev 39b1a12) ** DEBUGBUILD ** 
linux-unix-gnu-x86-64 [ 64bit manyargs dload ptables ]
compiled 2015-02-19 on devpool08 (Linux)

#;1> (features)
(srfi-18: files: lolevel: srfi-69: irregex: srfi-13: srfi-14: srfi-1: csi: ports: srfi-28: extras: data-structures: srfi-31: srfi-26: srfi-16: srfi-15: srfi-11: srfi-8: module-environments: hygienic-macros: syntax-rules: srfi-0: srfi-2: srfi-6: srfi-9: srfi-46: srfi-55: srfi-61: chicken-4: chicken-4.9: debugbuild: 64bit: ptables: dload: manyargs: little-endian: x86-64: gnu: linux: unix: chicken: srfi-6: srfi-10: srfi-23: srfi-30: srfi-39: srfi-62: srfi-17: srfi-12: srfi-88: srfi-98: irregex-is-core-unit:)