diff --git a/DESCRIPTION b/DESCRIPTION
index f5378ca6..45741b02 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -35,4 +35,4 @@ Suggests:
     tibble
 Enhances: knitr, shiny
 LazyData: true
-RoxygenNote: 6.0.1
+RoxygenNote: 7.1.1
diff --git a/R/sankeyNetwork.R b/R/sankeyNetwork.R
index 31f99ded..bf2f7ca4 100644
--- a/R/sankeyNetwork.R
+++ b/R/sankeyNetwork.R
@@ -41,6 +41,7 @@
 #' browser on the client so don't push it too high.
 #' @param sinksRight boolean. If \code{TRUE}, the last nodes are moved to the
 #' right border of the plot.
+#' @param arrows logical value to enable directional link arrows.
 #'
 #' @examples
 #' \dontrun{
@@ -76,7 +77,8 @@ sankeyNetwork <- function(Links, Nodes, Source, Target, Value,
     NodeID, NodeGroup = NodeID, LinkGroup = NULL, units = "",
     colourScale = JS("d3.scaleOrdinal(d3.schemeCategory20);"), fontSize = 7,
     fontFamily = NULL, nodeWidth = 15, nodePadding = 10, margin = NULL,
-    height = NULL, width = NULL, iterations = 32, sinksRight = TRUE)
+    height = NULL, width = NULL, iterations = 32, sinksRight = TRUE,
+    arrows=FALSE)
 {
     # Check if data is zero indexed
     check_zero(Links[, Source], Links[, Target])
@@ -132,7 +134,8 @@ sankeyNetwork <- function(Links, Nodes, Source, Target, Value,
     options = list(NodeID = NodeID, NodeGroup = NodeGroup, LinkGroup = LinkGroup,
         colourScale = colourScale, fontSize = fontSize, fontFamily = fontFamily,
         nodeWidth = nodeWidth, nodePadding = nodePadding, units = units,
-        margin = margin, iterations = iterations, sinksRight = sinksRight)
+        margin = margin, iterations = iterations, sinksRight = sinksRight,
+        arrows = arrows)
 
     # create widget
     htmlwidgets::createWidget(name = "sankeyNetwork", x = list(links = LinksDF,
diff --git a/inst/htmlwidgets/sankeyNetwork.js b/inst/htmlwidgets/sankeyNetwork.js
index 8fded80a..5dabfe47 100755
--- a/inst/htmlwidgets/sankeyNetwork.js
+++ b/inst/htmlwidgets/sankeyNetwork.js
@@ -121,7 +121,7 @@ HTMLWidgets.widget({
         var path = sankey.link();
 
         // draw links
-        var link = svg.selectAll(".link")
+        var link = svg.selectAll(".node")
             .data(links)
             .enter().append("path")
             .attr("class", "link")
@@ -140,6 +140,8 @@ HTMLWidgets.widget({
                 .style("stroke-opacity", opacity_link);
             });
 
+	
+
         // add backwards class to cycles
         link.classed('backwards', function (d) { return d.target.x < d.source.x; });
 
@@ -173,6 +175,30 @@ HTMLWidgets.widget({
             .html(function(d) { return "<pre>" + d.source.name + " \u2192 " + d.target.name +
                 "\n" + format(d.value) + " " + options.units + "</pre>"; });
 
+	if (options.arrows) {
+      	link.style("marker-end",  function(d) { return "url(#arrow-" + d.key + ")"; });
+
+      var linkColoursArr = d3.nest().key(function(d) { return d.colour; }).entries(links);
+
+      node.selectAll(".link")
+          .data(linkColoursArr)
+          .enter().append("marker")
+            .attr("id", function(d) { return "arrow-" + d.key; })
+            .attr("viewBox", "0, -5, 10, 10")
+            .attr("refX", 10)
+            .attr("refY", 0)
+            .attr("preserveAspectRatio", "xMaxYMin meet")
+            .attr("Width", sankey.nodeWidth())
+            .attr("markerHeight", 1)
+            .attr("orient", "auto-start-reverse")
+	    //.attr("transform", "skewY(40)")
+            .style("fill", "context-fill")
+            //.style("fill", function(d) { return d.key; })
+            .style("opacity", 0.5)
+          .append("path")
+            .attr("d", "M0,-5 L10,0 L0,5");
+    }		
+
         node.append("rect")
             .attr("height", function(d) { return d.dy; })
             .attr("width", sankey.nodeWidth())
diff --git a/man/MisLinks.Rd b/man/MisLinks.Rd
index 13542742..1cc76274 100644
--- a/man/MisLinks.Rd
+++ b/man/MisLinks.Rd
@@ -4,7 +4,9 @@
 \name{MisLinks}
 \alias{MisLinks}
 \title{Les Miserables character links}
-\format{A data set with 254 observations of 3 variables.}
+\format{
+A data set with 254 observations of 3 variables.
+}
 \source{
 See Mike Bostock \url{http://bl.ocks.org/mbostock/4062045}.
 }
diff --git a/man/MisNodes.Rd b/man/MisNodes.Rd
index c7cb5663..8cca267e 100644
--- a/man/MisNodes.Rd
+++ b/man/MisNodes.Rd
@@ -4,8 +4,10 @@
 \name{MisNodes}
 \alias{MisNodes}
 \title{Les Miserables character nodes}
-\format{A data set with 77 observations of 2 variables, plus made up
-node size variable.}
+\format{
+A data set with 77 observations of 2 variables, plus made up
+node size variable.
+}
 \source{
 See Mike Bostock \url{http://bl.ocks.org/mbostock/4062045}.
 }
diff --git a/man/SchoolsJournals.Rd b/man/SchoolsJournals.Rd
index 2ba5483e..cabcba5e 100644
--- a/man/SchoolsJournals.Rd
+++ b/man/SchoolsJournals.Rd
@@ -5,7 +5,9 @@
 \alias{SchoolsJournals}
 \title{Edge list of REF (2014) journal submissions for Politics and International
 Relations}
-\format{A data set with 2732 rows and 3 variables.}
+\format{
+A data set with 2732 rows and 3 variables.
+}
 \source{
 See REF 2014 \url{http://results.ref.ac.uk/DownloadSubmissions/ByUoa/21}.
 }
diff --git a/man/as_treenetdf.data.frame.Rd b/man/as_treenetdf.data.frame.Rd
index 3f108840..7cd4b436 100644
--- a/man/as_treenetdf.data.frame.Rd
+++ b/man/as_treenetdf.data.frame.Rd
@@ -4,8 +4,14 @@
 \alias{as_treenetdf.data.frame}
 \title{Convert a data.frame to a \code{treenetdf}}
 \usage{
-\method{as_treenetdf}{data.frame}(data, cols = setNames(names(data),
-  names(data)), df_type = "treenetdf", subset = names(data), root, ...)
+\method{as_treenetdf}{data.frame}(
+  data,
+  cols = setNames(names(data), names(data)),
+  df_type = "treenetdf",
+  subset = names(data),
+  root,
+  ...
+)
 }
 \arguments{
 \item{data}{a tree network description in one of numerous forms (see
diff --git a/man/as_treenetdf.list.Rd b/man/as_treenetdf.list.Rd
index e6ec2ee3..05fada3d 100644
--- a/man/as_treenetdf.list.Rd
+++ b/man/as_treenetdf.list.Rd
@@ -4,8 +4,7 @@
 \alias{as_treenetdf.list}
 \title{Convert a nested list to \code{treenetdf}}
 \usage{
-\method{as_treenetdf}{list}(data, children_name = "children",
-  node_name = "name", ...)
+\method{as_treenetdf}{list}(data, children_name = "children", node_name = "name", ...)
 }
 \arguments{
 \item{data}{a tree network description in one of numerous forms (see
diff --git a/man/chordNetwork.Rd b/man/chordNetwork.Rd
index 6b6d71c1..1f343454 100644
--- a/man/chordNetwork.Rd
+++ b/man/chordNetwork.Rd
@@ -7,12 +7,21 @@
 Mike Bostock: \url{https://github.com/mbostock/d3/wiki/Chord-Layout}.
 }
 \usage{
-chordNetwork(Data, height = 500, width = 500, initialOpacity = 0.8,
-  useTicks = 0, colourScale = c("#1f77b4", "#aec7e8", "#ff7f0e", "#ffbb78",
-  "#2ca02c", "#98df8a", "#d62728", "#ff9896", "#9467bd", "#c5b0d5", "#8c564b",
-  "#c49c94", "#e377c2", "#f7b6d2", "#7f7f7f", "#c7c7c7", "#bcbd22", "#dbdb8d",
-  "#17becf", "#9edae5"), padding = 0.1, fontSize = 14,
-  fontFamily = "sans-serif", labels = c(), labelDistance = 30)
+chordNetwork(
+  Data,
+  height = 500,
+  width = 500,
+  initialOpacity = 0.8,
+  useTicks = 0,
+  colourScale = c("#1f77b4", "#aec7e8", "#ff7f0e", "#ffbb78", "#2ca02c", "#98df8a",
+    "#d62728", "#ff9896", "#9467bd", "#c5b0d5", "#8c564b", "#c49c94", "#e377c2",
+    "#f7b6d2", "#7f7f7f", "#c7c7c7", "#bcbd22", "#dbdb8d", "#17becf", "#9edae5"),
+  padding = 0.1,
+  fontSize = 14,
+  fontFamily = "sans-serif",
+  labels = c(),
+  labelDistance = 30
+)
 }
 \arguments{
 \item{Data}{A square matrix or data frame whose (n, m) entry represents
diff --git a/man/dendroNetwork.Rd b/man/dendroNetwork.Rd
index feeb8fb9..6bd14c25 100644
--- a/man/dendroNetwork.Rd
+++ b/man/dendroNetwork.Rd
@@ -9,11 +9,23 @@ Mike Bostock: \url{http://bl.ocks.org/mbostock/4063570}.
 Fabio Nelli: \url{http://www.meccanismocomplesso.org/en/dendrogramma-d3-parte1/}
 }
 \usage{
-dendroNetwork(hc, height = 500, width = 800, fontSize = 10,
-  linkColour = "#ccc", nodeColour = "#fff", nodeStroke = "steelblue",
-  textColour = "#111", textOpacity = 0.9, textRotate = NULL,
-  opacity = 0.9, margins = NULL, linkType = c("elbow", "diagonal"),
-  treeOrientation = c("horizontal", "vertical"), zoom = FALSE)
+dendroNetwork(
+  hc,
+  height = 500,
+  width = 800,
+  fontSize = 10,
+  linkColour = "#ccc",
+  nodeColour = "#fff",
+  nodeStroke = "steelblue",
+  textColour = "#111",
+  textOpacity = 0.9,
+  textRotate = NULL,
+  opacity = 0.9,
+  margins = NULL,
+  linkType = c("elbow", "diagonal"),
+  treeOrientation = c("horizontal", "vertical"),
+  zoom = FALSE
+)
 }
 \arguments{
 \item{hc}{a hierarchical (\code{hclust}) cluster object.}
diff --git a/man/diagonalNetwork.Rd b/man/diagonalNetwork.Rd
index 2bc47050..4d054457 100644
--- a/man/diagonalNetwork.Rd
+++ b/man/diagonalNetwork.Rd
@@ -10,10 +10,19 @@ IEEE Transactions on Software Engineering, SE-7(2), 223-228.
 Mike Bostock: \url{http://bl.ocks.org/mbostock/4339083}.
 }
 \usage{
-diagonalNetwork(List, height = NULL, width = NULL, fontSize = 10,
-  fontFamily = "serif", linkColour = "#ccc", nodeColour = "#fff",
-  nodeStroke = "steelblue", textColour = "#111", opacity = 0.9,
-  margin = NULL)
+diagonalNetwork(
+  List,
+  height = NULL,
+  width = NULL,
+  fontSize = 10,
+  fontFamily = "serif",
+  linkColour = "#ccc",
+  nodeColour = "#fff",
+  nodeStroke = "steelblue",
+  textColour = "#111",
+  opacity = 0.9,
+  margin = NULL
+)
 }
 \arguments{
 \item{List}{a hierarchical list object with a root node and children.}
diff --git a/man/forceNetwork.Rd b/man/forceNetwork.Rd
index 2b97ba15..66875b56 100644
--- a/man/forceNetwork.Rd
+++ b/man/forceNetwork.Rd
@@ -9,15 +9,33 @@ specifically for force directed networks
 \url{https://github.com/d3/d3/blob/master/API.md#forces-d3-force}.
 }
 \usage{
-forceNetwork(Links, Nodes, Source, Target, Value, NodeID, Nodesize, Group,
-  height = NULL, width = NULL,
-  colourScale = JS("d3.scaleOrdinal(d3.schemeCategory20);"), fontSize = 7,
-  fontFamily = "serif", linkDistance = 50,
+forceNetwork(
+  Links,
+  Nodes,
+  Source,
+  Target,
+  Value,
+  NodeID,
+  Nodesize,
+  Group,
+  height = NULL,
+  width = NULL,
+  colourScale = JS("d3.scaleOrdinal(d3.schemeCategory20);"),
+  fontSize = 7,
+  fontFamily = "serif",
+  linkDistance = 50,
   linkWidth = JS("function(d) { return Math.sqrt(d.value); }"),
-  radiusCalculation = JS(" Math.sqrt(d.nodesize)+6"), charge = -30,
-  linkColour = "#666", opacity = 0.6, zoom = FALSE, legend = FALSE,
-  arrows = FALSE, bounded = FALSE, opacityNoHover = 0,
-  clickAction = NULL)
+  radiusCalculation = JS(" Math.sqrt(d.nodesize)+6"),
+  charge = -30,
+  linkColour = "#666",
+  opacity = 0.6,
+  zoom = FALSE,
+  legend = FALSE,
+  arrows = FALSE,
+  bounded = FALSE,
+  opacityNoHover = 0,
+  clickAction = NULL
+)
 }
 \arguments{
 \item{Links}{a data frame object with the links between the nodes. It should
diff --git a/man/radialNetwork.Rd b/man/radialNetwork.Rd
index 84313b2c..2b3f507e 100644
--- a/man/radialNetwork.Rd
+++ b/man/radialNetwork.Rd
@@ -10,10 +10,19 @@ IEEE Transactions on Software Engineering, SE-7(2), 223-228.
 Mike Bostock: \url{http://bl.ocks.org/mbostock/4063550}.
 }
 \usage{
-radialNetwork(List, height = NULL, width = NULL, fontSize = 10,
-  fontFamily = "serif", linkColour = "#ccc", nodeColour = "#fff",
-  nodeStroke = "steelblue", textColour = "#111", opacity = 0.9,
-  margin = NULL)
+radialNetwork(
+  List,
+  height = NULL,
+  width = NULL,
+  fontSize = 10,
+  fontFamily = "serif",
+  linkColour = "#ccc",
+  nodeColour = "#fff",
+  nodeStroke = "steelblue",
+  textColour = "#111",
+  opacity = 0.9,
+  margin = NULL
+)
 }
 \arguments{
 \item{List}{a hierarchical list object with a root node and children.}
diff --git a/man/sankeyNetwork.Rd b/man/sankeyNetwork.Rd
index 45445951..4d0a7799 100644
--- a/man/sankeyNetwork.Rd
+++ b/man/sankeyNetwork.Rd
@@ -8,11 +8,28 @@ D3.js was created by Michael Bostock. See \url{http://d3js.org/} and, more
 specifically for Sankey diagrams \url{http://bost.ocks.org/mike/sankey/}.
 }
 \usage{
-sankeyNetwork(Links, Nodes, Source, Target, Value, NodeID, NodeGroup = NodeID,
-  LinkGroup = NULL, units = "",
-  colourScale = JS("d3.scaleOrdinal(d3.schemeCategory20);"), fontSize = 7,
-  fontFamily = NULL, nodeWidth = 15, nodePadding = 10, margin = NULL,
-  height = NULL, width = NULL, iterations = 32, sinksRight = TRUE)
+sankeyNetwork(
+  Links,
+  Nodes,
+  Source,
+  Target,
+  Value,
+  NodeID,
+  NodeGroup = NodeID,
+  LinkGroup = NULL,
+  units = "",
+  colourScale = JS("d3.scaleOrdinal(d3.schemeCategory20);"),
+  fontSize = 7,
+  fontFamily = NULL,
+  nodeWidth = 15,
+  nodePadding = 10,
+  margin = NULL,
+  height = NULL,
+  width = NULL,
+  iterations = 32,
+  sinksRight = TRUE,
+  arrows = FALSE
+)
 }
 \arguments{
 \item{Links}{a data frame object with the links between the nodes. It should
@@ -74,6 +91,8 @@ browser on the client so don't push it too high.}
 
 \item{sinksRight}{boolean. If \code{TRUE}, the last nodes are moved to the
 right border of the plot.}
+
+\item{arrows}{logical value to enable directional link arrows.}
 }
 \description{
 Create a D3 JavaScript Sankey diagram
diff --git a/man/simpleNetwork.Rd b/man/simpleNetwork.Rd
index 217573b5..e96b1f4f 100644
--- a/man/simpleNetwork.Rd
+++ b/man/simpleNetwork.Rd
@@ -9,9 +9,21 @@ D3.js was created by Michael Bostock. See \url{http://d3js.org/} and,
   \url{https://github.com/d3/d3/blob/master/API.md#forces-d3-force}
 }
 \usage{
-simpleNetwork(Data, Source = 1, Target = 2, height = NULL, width = NULL,
-  linkDistance = 50, charge = -30, fontSize = 7, fontFamily = "serif",
-  linkColour = "#666", nodeColour = "#3182bd", opacity = 0.6, zoom = F)
+simpleNetwork(
+  Data,
+  Source = 1,
+  Target = 2,
+  height = NULL,
+  width = NULL,
+  linkDistance = 50,
+  charge = -30,
+  fontSize = 7,
+  fontFamily = "serif",
+  linkColour = "#666",
+  nodeColour = "#3182bd",
+  opacity = 0.6,
+  zoom = F
+)
 }
 \arguments{
 \item{Data}{a data frame object with three columns. The first two are the
diff --git a/man/treeNetwork.Rd b/man/treeNetwork.Rd
index 76f13030..22264de3 100644
--- a/man/treeNetwork.Rd
+++ b/man/treeNetwork.Rd
@@ -4,9 +4,19 @@
 \alias{treeNetwork}
 \title{Create collapsible tree network diagrams.}
 \usage{
-treeNetwork(data, width = NULL, height = NULL, treeType = "tidy",
-  direction = "right", linkType = "diagonal", defaults = NULL,
-  mouseover = "", mouseout = "", inbrowser = FALSE, ...)
+treeNetwork(
+  data,
+  width = NULL,
+  height = NULL,
+  treeType = "tidy",
+  direction = "right",
+  linkType = "diagonal",
+  defaults = NULL,
+  mouseover = "",
+  mouseout = "",
+  inbrowser = FALSE,
+  ...
+)
 }
 \arguments{
 \item{data}{a tree network description in one of numerous forms (see details)}