--- a/glquake.h
+++ b/glquake.h
@@ -977,6 +977,7 @@
 #define GL_MAP2_VERTEX_ATTRIB15_4_NV      0x867F
 
 /* NV_vertex_program */
+#ifndef GL_NV_vertex_program
 typedef GLboolean (APIENTRY * PFNGLAREPROGRAMSRESIDENTNVPROC) (GLsizei n, const GLuint *programs, GLboolean *residences);
 typedef void (APIENTRY * PFNGLBINDPROGRAMNVPROC) (GLenum target, GLuint id);
 typedef void (APIENTRY * PFNGLDELETEPROGRAMSNVPROC) (GLsizei n, const GLuint *programs);
@@ -1040,6 +1041,7 @@
 typedef void (APIENTRY * PFNGLVERTEXATTRIBS4FVNVPROC) (GLuint index, GLsizei count, const GLfloat *v);
 typedef void (APIENTRY * PFNGLVERTEXATTRIBS4SVNVPROC) (GLuint index, GLsizei count, const GLshort *v);
 typedef void (APIENTRY * PFNGLVERTEXATTRIBS4UBVNVPROC) (GLuint index, GLsizei count, const GLubyte *v);
+#endif
 
 extern PFNGLAREPROGRAMSRESIDENTNVPROC qglAreProgramsResidentNV ;
 extern PFNGLBINDPROGRAMNVPROC qglBindProgramNV ;