diff --git a/NAMESPACE b/NAMESPACE
index 25dfbd98e..57472a5bf 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -44,6 +44,7 @@ S3method(as.data.table, ordered)
 S3method(as.data.table, Date)
 S3method(as.data.table, table)
 S3method(as.data.table, xts)
+S3method(as.data.table, default)
 S3method(as.data.frame, data.table)
 S3method(as.list, data.table)
 S3method(as.matrix, data.table)
diff --git a/R/data.table.R b/R/data.table.R
index e514d5287..041c504e1 100644
--- a/R/data.table.R
+++ b/R/data.table.R
@@ -1632,7 +1632,7 @@ as.matrix.data.table <- function(x,...)
     X
 }
 
-as.data.table.matrix <- function(x, keep.rownames=FALSE)
+as.data.table.matrix <- function(x, keep.rownames=FALSE, ...)
 {
     if (keep.rownames) return(data.table(rn=rownames(x), x, keep.rownames=FALSE))
     d <- dim(x)
@@ -1661,7 +1661,7 @@ as.data.table.matrix <- function(x, keep.rownames=FALSE)
     alloc.col(value)
 }
 
-as.data.table.data.frame <- function(x, keep.rownames=FALSE)
+as.data.table.data.frame <- function(x, keep.rownames=FALSE, ...)
 {
     if (keep.rownames) return(data.table(rn=rownames(x), x, keep.rownames=FALSE))
     ans = copy(x)  # TO DO: change this deep copy to be shallow.
@@ -1675,7 +1675,7 @@ as.data.table.data.frame <- function(x, keep.rownames=FALSE)
     alloc.col(ans)
 }
 
-as.data.table.list <- function(x, keep.rownames=FALSE) {
+as.data.table.list <- function(x, keep.rownames=FALSE, ...) {
     if (!length(x)) return( null.data.table() )
     n = vapply(x, length, 0L)
     mn = max(n)
@@ -1697,13 +1697,13 @@ as.data.table.list <- function(x, keep.rownames=FALSE) {
     alloc.col(x)
 }
 
-as.data.table.data.table <- function(x, keep.rownames=FALSE) return(x)
+as.data.table.data.table <- function(x, keep.rownames=FALSE, ...) return(x)
 
 # takes care of logical, character, numeric, integer
 as.data.table.factor <- as.data.table.ordered <- 
 as.data.table.integer <- as.data.table.numeric <- 
 as.data.table.logical <- as.data.table.character <- 
-as.data.table.Date <- function(x, keep.rownames=FALSE) {
+as.data.table.Date <- function(x, keep.rownames=FALSE, ...) {
     tt = deparse(substitute(x))[1]
     nm = names(x)
     # FR #2356 - transfer names of named vector as "rn" column if required
@@ -1734,7 +1734,7 @@ R300_provideDimnames <- function (x, sep = "", base = list(LETTERS))   # backpor
 }
 
 # as.data.table.table - FR #4848
-as.data.table.table <- function(x, keep.rownames=FALSE) {
+as.data.table.table <- function(x, keep.rownames=FALSE, ...) {
     # Fix for bug #5408 - order of columns are different when doing as.data.table(with(DT, table(x, y)))
     val = rev(dimnames(R300_provideDimnames(x)))
     if (is.null(names(val)) || all(nchar(names(val)) == 0L)) 
@@ -1836,13 +1836,17 @@ tail.data.table <- function(x, n=6, ...) {
     `[<-.data.table`(x,j=name,value=value)  # important i is missing here
 }
 
-as.data.table <-function(x, keep.rownames=FALSE)
+as.data.table <-function(x, keep.rownames=FALSE, ...)
 {
     if (is.null(x))
         return(null.data.table())
     UseMethod("as.data.table")
 }
 
+as.data.table.default <- function(x, ...){
+  setDT(as.data.frame(x, ...))[]
+}
+
 as.data.frame.data.table <- function(x, ...)
 {
     ans = copy(x)
diff --git a/R/xts.R b/R/xts.R
index 0c07f7e3c..24c90db52 100644
--- a/R/xts.R
+++ b/R/xts.R
@@ -1,4 +1,4 @@
-as.data.table.xts <- function(x, keep.rownames = TRUE){
+as.data.table.xts <- function(x, keep.rownames = TRUE, ...){
   stopifnot(requireNamespace("xts"), !missing(x), xts::is.xts(x))
   if(!keep.rownames) return(setDT(as.data.frame(x, row.names=FALSE))[])
   if("index" %in% names(x)) stop("Input xts object should not have 'index' column because it would result in duplicate column names. Rename 'index' column in xts or use `keep.rownames=FALSE` and add index manually as another column.")
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 1a570e1ef..94fa331db 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -5741,6 +5741,12 @@ if ("package:xts" %in% search()) {
     test(1465.4, xt, xt_dt)
 }
 
+# as.data.table.default #969
+ar <- array(NA, dim=c(10,4),dimnames = list(NULL,paste0("col",1:4)))
+test(1466.1, as.data.table(as.data.frame(ar)), as.data.table(ar)) # array type
+x <- rep(Sys.time(),3)
+test(1466.2, as.data.table(as.data.frame(x)), as.data.table(x)) # posix type
+
 ##########################
 
 
diff --git a/man/as.data.table.xts.Rd b/man/as.data.table.xts.Rd
index 52f0746ab..a38fe2b7f 100644
--- a/man/as.data.table.xts.Rd
+++ b/man/as.data.table.xts.Rd
@@ -5,12 +5,14 @@
   Efficient conversion xts to data.table.
 }
 \usage{
-\method{as.data.table}{xts}(x, keep.rownames = TRUE)
+\method{as.data.table}{xts}(x, keep.rownames = TRUE, ...)
 }
 \arguments{
 \item{x}{xts to convert to data.table}
 
 \item{keep.rownames}{keep xts index as \emph{index} column in result data.table}
+
+\item{\dots}{ignored, just for consistency with \code{as.data.table}}
 }
 \seealso{ \code{\link{as.xts.data.table}} }
 \examples{