diff --git a/main/io.c b/main/io.c
index 1c4d5f4e00..ced692180a 100644
--- a/main/io.c
+++ b/main/io.c
@@ -57,7 +57,7 @@ struct io_rec {
    the same index.  it's too bad that
    pollfd doesn't have a callback field
    or something like that.  They grow as
-   needed, by GROW_SHRINK_AMOUNT structures
+   needed, by GROW_SHRINK_SIZE structures
    at once */
 
 #define GROW_SHRINK_SIZE 512