diff --git a/src/lib-stream.c b/src/lib-stream.c
index eb46f1b..faeb4d4 100644
--- a/src/lib-stream.c
+++ b/src/lib-stream.c
@@ -23,8 +23,9 @@
 /* Needed for getc_unlocked() on OpenSolaris */
 #define __EXTENSIONS__
 
-#if defined HAVE___SREFILL || defined HAVE___FILBUF
-#   define HAVE_REFILL_STDIO
+/* Define if stdio operations use *only* the refill mechanism */
+#if defined HAVE___SREFILL
+#   define REFILL_ONLY_STDIO
 #endif
 
 #if defined HAVE_STDINT_H
@@ -36,7 +37,7 @@
 
 #include <stdio.h>
 #include <sys/types.h>
-#if defined HAVE_REFILL_STDIO && defined HAVE_UNISTD_H
+#if defined HAVE_UNISTD_H
 #   include <unistd.h> /* Needed for __srefill’s lseek() call */
 #endif
 
@@ -144,7 +145,7 @@ int            (*ORIG(__filbuf))  (FILE *fp);
 #endif
 
 /* Our function wrappers */
-#if defined HAVE_REFILL_STDIO /* Fuzz fp if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Fuzz fp if we have __srefill() */
 #   define FOPEN_FUZZ() \
     _zz_fuzz(fd, ret->FILE_PTR, ret->FILE_CNT)
 #else
@@ -231,7 +232,7 @@ FILE *NEW(__freopen64)(const char *path, const char *mode, FILE *stream)
 }
 #endif
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #   define FSEEK_FUZZ(fn2)
 #else
 #   define FSEEK_FUZZ(fn2) \
@@ -343,14 +344,14 @@ void NEW(rewind)(FILE *stream)
     _zz_unlock(fd);
     debug("%s([%i])", __func__, fd);
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #else
     /* FIXME: check what happens when rewind()ing a pipe */
     _zz_setpos(fd, 0);
 #endif
 }
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #   define FREAD_FUZZ() \
     do \
     { \
@@ -420,7 +421,7 @@ size_t NEW(fread_unlocked)(void *ptr, size_t size, size_t nmemb, FILE *stream)
 }
 #endif
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #   define FGETC_FUZZ
 #else
 #   define FGETC_FUZZ \
@@ -498,7 +499,7 @@ int NEW(fgetc_unlocked)(FILE *stream)
 }
 #endif
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #   define FGETS_FUZZ(fn, fn2) \
         _zz_lock(fd); \
         ret = ORIG(fn)(s, size, stream); \
@@ -582,7 +583,7 @@ int NEW(ungetc)(int c, FILE *stream)
         fuzz->uflag = 1;
         fuzz->upos = _zz_getpos(fd) - 1;
         fuzz->uchar = c;
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #else
         _zz_addpos(fd, -1);
 #endif
@@ -695,7 +696,7 @@ ssize_t NEW(__getdelim)(char **lineptr, size_t *n, int delim, FILE *stream)
 char *NEW(fgetln)(FILE *stream, size_t *len)
 {
     char *ret;
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
 #else
     struct fuzz *fuzz;
     size_t i, size;
@@ -708,7 +709,7 @@ char *NEW(fgetln)(FILE *stream, size_t *len)
     if(!_zz_ready || !_zz_iswatched(fd) || !_zz_isactive(fd))
         return ORIG(fgetln)(stream, len);
 
-#if defined HAVE_REFILL_STDIO /* Don't fuzz or seek if we have __srefill() */
+#if defined REFILL_ONLY_STDIO /* Don't fuzz or seek if we have __srefill() */
     _zz_lock(fd);
     ret = ORIG(fgetln)(stream, len);
     _zz_unlock(fd);