--- chicken.h.orig
+++ chicken.h
@@ -976,11 +976,7 @@ DECL_C_PROC_p0 (128,  1,0,0,0,0,0,0,0)
 # define C_fputs                    fputs
 # define C_fputc                    fputc
 # define C_putchar                  putchar
-# if (defined getc_unlocked || _POSIX_C_SOURCE >= 199506L)
-#  define C_getc                    getc_unlocked
-# else
-#  define C_getc                    getc
-# endif
+# define C_getc                     getc
 # define C_fgetc                    fgetc
 # define C_fgets                    fgets
 # define C_ungetc                   ungetc
