diff --git a/R/read_delim.R b/R/read_delim.R
index f1137628..18623009 100644
--- a/R/read_delim.R
+++ b/R/read_delim.R
@@ -82,9 +82,9 @@ NULL
 #' @param lazy Read values lazily? By default the file is initially only
 #'   indexed and the values are read lazily when accessed. Lazy reading is
 #'   useful interactively, particularly if you are only interested in a subset
-#'   of the full dataset. Note, lazy reading on windows will lock the file
-#'   until all the data has been read from it, if you run into this issue set
-#'   `lazy = FALSE`.
+#'   of the full dataset. *Note*, if you later write to the same file you read
+#'   from you need to set `lazy = FALSE`. On Windows the file will be locked
+#'   and on other systems the memory map will become invalid.
 #' @param num_threads The number of processing threads to use for initial
 #'   parsing and lazy reading of data. If your data contains newlines within
 #'   fields the parser should automatically detect this and fall back to using
diff --git a/man/read_delim.Rd b/man/read_delim.Rd
index d1084d06..745f6727 100644
--- a/man/read_delim.Rd
+++ b/man/read_delim.Rd
@@ -253,9 +253,9 @@ option is \code{TRUE} then blank rows will not be represented at all.  If it is
 \item{lazy}{Read values lazily? By default the file is initially only
 indexed and the values are read lazily when accessed. Lazy reading is
 useful interactively, particularly if you are only interested in a subset
-of the full dataset. Note, lazy reading on windows will lock the file
-until all the data has been read from it, if you run into this issue set
-\code{lazy = FALSE}.}
+of the full dataset. \emph{Note}, if you later write to the same file you read
+from you need to set \code{lazy = FALSE}. On Windows the file will be locked
+and on other systems the memory map will become invalid.}
 }
 \value{
 A \code{\link[=tibble]{tibble()}}. If there are parsing problems, a warning will alert you.
diff --git a/man/read_fwf.Rd b/man/read_fwf.Rd
index c29783a3..82efd040 100644
--- a/man/read_fwf.Rd
+++ b/man/read_fwf.Rd
@@ -163,9 +163,9 @@ by the \code{col_types} argument.}
 \item{lazy}{Read values lazily? By default the file is initially only
 indexed and the values are read lazily when accessed. Lazy reading is
 useful interactively, particularly if you are only interested in a subset
-of the full dataset. Note, lazy reading on windows will lock the file
-until all the data has been read from it, if you run into this issue set
-\code{lazy = FALSE}.}
+of the full dataset. \emph{Note}, if you later write to the same file you read
+from you need to set \code{lazy = FALSE}. On Windows the file will be locked
+and on other systems the memory map will become invalid.}
 
 \item{skip_empty_rows}{Should blank rows be ignored altogether? i.e. If this
 option is \code{TRUE} then blank rows will not be represented at all.  If it is
diff --git a/man/read_lines.Rd b/man/read_lines.Rd
index c49ab641..07302365 100644
--- a/man/read_lines.Rd
+++ b/man/read_lines.Rd
@@ -73,9 +73,9 @@ option to \code{character()} to indicate no missing values.}
 \item{lazy}{Read values lazily? By default the file is initially only
 indexed and the values are read lazily when accessed. Lazy reading is
 useful interactively, particularly if you are only interested in a subset
-of the full dataset. Note, lazy reading on windows will lock the file
-until all the data has been read from it, if you run into this issue set
-\code{lazy = FALSE}.}
+of the full dataset. \emph{Note}, if you later write to the same file you read
+from you need to set \code{lazy = FALSE}. On Windows the file will be locked
+and on other systems the memory map will become invalid.}
 
 \item{num_threads}{The number of processing threads to use for initial
 parsing and lazy reading of data. If your data contains newlines within
diff --git a/man/spec_delim.Rd b/man/spec_delim.Rd
index ee49d103..a92932e4 100644
--- a/man/spec_delim.Rd
+++ b/man/spec_delim.Rd
@@ -268,9 +268,9 @@ option is \code{TRUE} then blank rows will not be represented at all.  If it is
 \item{lazy}{Read values lazily? By default the file is initially only
 indexed and the values are read lazily when accessed. Lazy reading is
 useful interactively, particularly if you are only interested in a subset
-of the full dataset. Note, lazy reading on windows will lock the file
-until all the data has been read from it, if you run into this issue set
-\code{lazy = FALSE}.}
+of the full dataset. \emph{Note}, if you later write to the same file you read
+from you need to set \code{lazy = FALSE}. On Windows the file will be locked
+and on other systems the memory map will become invalid.}
 }
 \value{
 The \code{col_spec} generated for the file.