[gambit-list] C interface: wrong types generated?

I don't know if the compiler is generating the wrong type, or i'm doing something wrong...

I've written an OpenGL + GLU binding for Gambit-C, which is (I think and hope) 100% done, except for this type error:

glColor.c: In function '___H__20_glColor_23_16': glColor.c:1558: warning: pointer targets in passing argument 1 of 'glColor3bv' differ in signedness glColor.c: In function '___H__20_glColor_23_24': glColor.c:1982: warning: pointer targets in passing argument 1 of 'glColor4bv' differ in signedness glNormal.c: In function '___H__20_glNormal_23_5': glNormal.c:563: warning: pointer targets in passing argument 1 of 'glNormal3bv' differ in signedness

All three of these mismatched arguments have the same type. Here's the type in C:

typedef signed char GLbyte; /* 1-byte signed */

And in Gambit-C:

(c-define-type GLbytesigned-char) (c-define-type GLbyte* (pointer GLbyte))

GLAPI void GLAPIENTRY glNormal3bv( const GLbyte *v );

TJay ~