diff --git a/auto/src/glew_init_tail.c b/auto/src/glew_init_tail.c
index 678b91c..a4dbb81 100644
--- a/auto/src/glew_init_tail.c
+++ b/auto/src/glew_init_tail.c
@@ -40,10 +40,11 @@ extern GLenum wglewContextInit (void);
 extern GLenum glxewContextInit (void);
 #endif /* _WIN32 */
 
-GLenum glewInit ()
+GLenum glewInit (void)
 {
   GLenum r;
-  if ( (r = glewContextInit()) ) return r;
+  r = glewContextInit();
+  if ( r != 0 ) return r;
 #if defined(_WIN32)
   return wglewContextInit();
 #elif !defined(__APPLE__) || defined(GLEW_APPLE_GLX) /* _UNIX */