diff --git a/lib/read-file.c b/lib/read-file.c
index 0a15c5a..4ea38f7 100644
--- a/lib/read-file.c
+++ b/lib/read-file.c
@@ -65,7 +65,8 @@ fread_file (FILE * stream, size_t * length)
                 return NULL;
               }
 
-            alloc = alloc_off + 1;
+            /* 1 > file size so eof immediately detected.  */
+            alloc = alloc_off + 2;
 
             buf = malloc (alloc);
             if (!buf)
@@ -120,8 +121,10 @@ fread_file (FILE * stream, size_t * length)
             if (ferror (stream))
               break;
 
-            /* Shrink the allocated memory if possible.  */
-            if (size + 1 < alloc)
+            /* Shrink the allocated memory if possible,
+               but don't bother about the extra byte
+               allocated to detect the eof.  */
+            if (size < alloc - 2)
               {
                 char *smaller_buf = realloc (buf, size + 1);
                 if (smaller_buf != NULL)