diff --git a/lib/codemirror.css b/lib/codemirror.css
index b962b38374..5ef92dfaf0 100644
--- a/lib/codemirror.css
+++ b/lib/codemirror.css
@@ -27,6 +27,10 @@
   background-color: #f7f7f7;
   white-space: nowrap;
 }
+.CodeMirror-rtl .CodeMirror-gutters {
+  border-right: none;
+  border-left: 1px solid #ddd;
+}
 .CodeMirror-linenumbers {}
 .CodeMirror-linenumber {
   padding: 0 3px 0 5px;
@@ -165,10 +169,22 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
   outline: none; /* Prevent dragging from highlighting the element */
   position: relative;
 }
+
+.CodeMirror-rtl .CodeMirror-scroll {
+  /* 30px is the magic margin used to hide the element's real scrollbars */
+  /* See overflow: hidden in .CodeMirror */
+  margin-left: -30px;
+  margin-right: 0;
+}
+
 .CodeMirror-sizer {
   position: relative;
   border-right: 30px solid transparent;
 }
+.CodeMirror-rtl .CodeMirror-sizer {
+  border-right: 0;
+  border-left: 30px solid transparent;
+}
 
 /* The fake, visible scrollbars. Used to force redraw during scrolling
    before actual scrolling happens, thus preventing shaking and
@@ -183,6 +199,9 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
   overflow-x: hidden;
   overflow-y: scroll;
 }
+.CodeMirror-rtl .CodeMirror-vscrollbar {
+  left: 0; right: initial;
+}
 .CodeMirror-hscrollbar {
   bottom: 0; left: 0;
   overflow-y: hidden;
@@ -191,15 +210,22 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
 .CodeMirror-scrollbar-filler {
   right: 0; bottom: 0;
 }
+.CodeMirror-rtl .CodeMirror-scrollbar-filler {
+  right: initial; left: 0;
+}
 .CodeMirror-gutter-filler {
   left: 0; bottom: 0;
 }
+.CodeMirror-rtl .CodeMirror-gutter-filler {
+  left: initial; right: 0;
+}
 
 .CodeMirror-gutters {
   position: absolute; left: 0; top: 0;
   min-height: 100%;
   z-index: 3;
 }
+.CodeMirror-rtl .CodeMirror-gutters { left: initial }
 .CodeMirror-gutter {
   white-space: normal;
   height: 100%;
@@ -269,7 +295,7 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #f22;}
 
 .CodeMirror-widget {}
 
-.CodeMirror-rtl pre { direction: rtl; }
+.CodeMirror-rtl { direction: rtl; }
 
 .CodeMirror-code {
   outline: none;
diff --git a/src/display/line_numbers.js b/src/display/line_numbers.js
index c48f2204d5..01642ce842 100644
--- a/src/display/line_numbers.js
+++ b/src/display/line_numbers.js
@@ -9,21 +9,52 @@ import { updateGutterSpace } from "./update_display"
 export function alignHorizontally(cm) {
   let display = cm.display, view = display.view
   if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return
-  let comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft
-  let gutterW = display.gutters.offsetWidth, left = comp + "px"
+  let isLtr = cm.doc.direction == "ltr"
+  let scroll = display.scroller.scrollLeft - cm.doc.scrollLeft
+  let comp = compensateForHScroll(display, isLtr) + (isLtr ? -scroll : scroll)
+  let offset = comp + "px"
+  let side = isLtr ? "left" : "right"
+  let otherSide = isLtr ? "right" : "left"
   for (let i = 0; i < view.length; i++) if (!view[i].hidden) {
     if (cm.options.fixedGutter) {
-      if (view[i].gutter)
-        view[i].gutter.style.left = left
-      if (view[i].gutterBackground)
-        view[i].gutterBackground.style.left = left
+      if (view[i].gutter) {
+        view[i].gutter.style[side] = offset
+        view[i].gutter.style[otherSide] = null
+      }
+      if (view[i].gutterBackground) {
+        view[i].gutterBackground.style[side] = offset
+        view[i].gutterBackground.style[otherSide] = null
+      }
     }
     let align = view[i].alignable
-    if (align) for (let j = 0; j < align.length; j++)
-      align[j].style.left = left
+    if (align) for (let j = 0; j < align.length; j++) {
+      align[j].style[side] = offset
+      align[j].style[otherSide] = null
+    }
   }
-  if (cm.options.fixedGutter)
-    display.gutters.style.left = (comp + gutterW) + "px"
+  setGutterOffset(cm)
+}
+
+function setGutterOffset(cm, fixed = cm.options.fixedGutter, alsoIfNotFixed = false) {
+  let isLtr = cm.doc.direction == "ltr"
+  let side = isLtr ? "left" : "right"
+  let display = cm.display
+  if (!fixed) {
+    if (alsoIfNotFixed) {
+      display.gutters.style[side] = "0"
+      display.gutters.style[isLtr ? "right" : "left"] = null
+    }
+    return
+  }
+  let scroll = display.scroller.scrollLeft - cm.doc.scrollLeft
+  let comp = compensateForHScroll(display, isLtr) + (isLtr ? -scroll : scroll)
+  let gutterW = display.gutters.offsetWidth
+  display.gutters.style[side] = (comp + gutterW) + "px"
+  display.gutters.style[isLtr ? "right" : "left"] = null
+}
+
+export function updateFixedGutter(cm, val) {
+  setGutterOffset(cm, val, true)
 }
 
 // Used to ensure that the line number gutter is still the right
diff --git a/src/display/operations.js b/src/display/operations.js
index 6c4a0e1392..b3a9be5a3a 100644
--- a/src/display/operations.js
+++ b/src/display/operations.js
@@ -1,6 +1,7 @@
 import { clipPos } from "../line/pos"
 import { findMaxLine } from "../line/spans"
 import { displayWidth, measureChar, scrollGap } from "../measurement/position_measurement"
+import { gecko } from "../util/browser"
 import { signal } from "../util/event"
 import { activeElt } from "../util/dom"
 import { finishOperation, pushOperation } from "../util/operation_group"
@@ -100,7 +101,7 @@ function endOperation_R2(op) {
     cm.display.sizerWidth = op.adjustWidthTo
     op.barMeasure.scrollWidth =
       Math.max(display.scroller.clientWidth, display.sizer.offsetLeft + op.adjustWidthTo + scrollGap(cm) + cm.display.barWidth)
-    op.maxScrollLeft = Math.max(0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm))
+    op.maxScrollLeft = Math[gecko && cm.doc.direction == "rtl" ? "min" : "max"](0, display.sizer.offsetLeft + op.adjustWidthTo - displayWidth(cm))
   }
 
   if (op.updatedDisplay || op.selectionChanged)
diff --git a/src/display/scrollbars.js b/src/display/scrollbars.js
index d03850be0f..cb5921ed21 100644
--- a/src/display/scrollbars.js
+++ b/src/display/scrollbars.js
@@ -65,8 +65,8 @@ class NativeScrollbars {
 
     if (needsH) {
       this.horiz.style.display = "block"
-      this.horiz.style.right = needsV ? sWidth + "px" : "0"
-      this.horiz.style.left = measure.barLeft + "px"
+      this.horiz.style[this.cm.doc.direction == "ltr" ? "right" : "left"] = needsV ? sWidth + "px" : "0"
+      this.horiz.style[this.cm.doc.direction == "ltr" ? "left" : "right"] = measure.barLeft + "px"
       let totalWidth = measure.viewWidth - measure.barLeft - (needsV ? sWidth : 0)
       this.horiz.firstChild.style.width =
         Math.max(0, measure.scrollWidth - measure.clientWidth + totalWidth) + "px"
@@ -150,7 +150,8 @@ function updateScrollbarsInner(cm, measure) {
   let d = cm.display
   let sizes = d.scrollbars.update(measure)
 
-  d.sizer.style.paddingRight = (d.barWidth = sizes.right) + "px"
+  d.sizer.style[cm.doc.direction == "ltr" ? "paddingRight" : "paddingLeft"] = (d.barWidth = sizes.right) + "px"
+  d.sizer.style[cm.doc.direction == "ltr" ? "paddingLeft" : "paddingRight"] = 0
   d.sizer.style.paddingBottom = (d.barHeight = sizes.bottom) + "px"
   d.heightForcer.style.borderBottom = sizes.bottom + "px solid transparent"
 
diff --git a/src/display/scrolling.js b/src/display/scrolling.js
index b2deb2ed64..110a62c934 100644
--- a/src/display/scrolling.js
+++ b/src/display/scrolling.js
@@ -86,10 +86,11 @@ export function calculateScrollPos(cm, rect) {
   let screenw = displayWidth(cm) - (cm.options.fixedGutter ? display.gutters.offsetWidth : 0)
   let tooWide = rect.right - rect.left > screenw
   if (tooWide) rect.right = rect.left + screenw
-  if (rect.left < 10)
+  let rtl = cm.doc.direction == "rtl"
+  if (Math.abs(rect.left) < 10 || (rtl ? rect.left > 0 : rect.left < 0))
     result.scrollLeft = 0
   else if (rect.left < screenleft)
-    result.scrollLeft = Math.max(0, rect.left - (tooWide ? 0 : 10))
+    result.scrollLeft = Math[rtl ? "min" : "max"](0, rect.left - (tooWide ? 0 : 10))
   else if (rect.right > screenw + screenleft - 3)
     result.scrollLeft = rect.right + (tooWide ? 0 : 10) - screenw
   return result
diff --git a/src/display/selection.js b/src/display/selection.js
index d9b69d4921..9b69e625b8 100644
--- a/src/display/selection.js
+++ b/src/display/selection.js
@@ -92,7 +92,7 @@ function drawSelectionRange(cm, range, output) {
         start = leftPos
       if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
         end = rightPos
-      if (left < leftSide + 1) left = leftSide
+      if (left < leftSide + 1 && cm.doc.direction != "rtl") left = leftSide
       add(left, rightPos.top, right - left, rightPos.bottom)
     })
     return {start: start, end: end}
diff --git a/src/display/update_display.js b/src/display/update_display.js
index 17d5a069e5..c4ee8fb8f6 100644
--- a/src/display/update_display.js
+++ b/src/display/update_display.js
@@ -49,7 +49,8 @@ export function maybeClipScrollbars(cm) {
     display.nativeBarWidth = display.scroller.offsetWidth - display.scroller.clientWidth
     display.heightForcer.style.height = scrollGap(cm) + "px"
     display.sizer.style.marginBottom = -display.nativeBarWidth + "px"
-    display.sizer.style.borderRightWidth = scrollGap(cm) + "px"
+    display.sizer.style[cm.doc.direction == "ltr" ? "borderLeftWidth" : "borderRightWidth"] = null
+    display.sizer.style[cm.doc.direction == "ltr" ? "borderRightWidth" : "borderLeftWidth"] = scrollGap(cm) + "px"
     display.scrollbarsClipped = true
   }
 }
@@ -219,7 +220,8 @@ function patchDisplay(cm, updateNumbersFrom, dims) {
 
 export function updateGutterSpace(cm) {
   let width = cm.display.gutters.offsetWidth
-  cm.display.sizer.style.marginLeft = width + "px"
+  cm.display.sizer.style[cm.doc.direction == "ltr" ? "marginRight" : "marginLeft"] = null
+  cm.display.sizer.style[cm.doc.direction == "ltr" ? "marginLeft" : "marginRight"] = width + "px"
 }
 
 export function setDocumentHeight(cm, measure) {
diff --git a/src/display/update_line.js b/src/display/update_line.js
index 15a2394257..2db1bac459 100644
--- a/src/display/update_line.js
+++ b/src/display/update_line.js
@@ -93,17 +93,18 @@ function updateLineGutter(cm, lineView, lineN, dims) {
     lineView.node.removeChild(lineView.gutterBackground)
     lineView.gutterBackground = null
   }
+  let side = (cm.doc.direction == "ltr" ? "left" : "right")
   if (lineView.line.gutterClass) {
     let wrap = ensureLineWrapped(lineView)
     lineView.gutterBackground = elt("div", null, "CodeMirror-gutter-background " + lineView.line.gutterClass,
-                                    `left: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px; width: ${dims.gutterTotalWidth}px`)
+                                    `${side}: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px; width: ${dims.gutterTotalWidth}px`)
     cm.display.input.setUneditable(lineView.gutterBackground)
     wrap.insertBefore(lineView.gutterBackground, lineView.text)
   }
   let markers = lineView.line.gutterMarkers
   if (cm.options.lineNumbers || markers) {
     let wrap = ensureLineWrapped(lineView)
-    let gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", `left: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px`)
+    let gutterWrap = lineView.gutter = elt("div", null, "CodeMirror-gutter-wrapper", `${side}: ${cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth}px`)
     cm.display.input.setUneditable(gutterWrap)
     wrap.insertBefore(gutterWrap, lineView.text)
     if (lineView.line.gutterClass)
@@ -112,12 +113,12 @@ function updateLineGutter(cm, lineView, lineN, dims) {
       lineView.lineNumber = gutterWrap.appendChild(
         elt("div", lineNumberFor(cm.options, lineN),
             "CodeMirror-linenumber CodeMirror-gutter-elt",
-            `left: ${dims.gutterLeft["CodeMirror-linenumbers"]}px; width: ${cm.display.lineNumInnerWidth}px`))
+            `${side}: ${dims.gutterLeft["CodeMirror-linenumbers"]}px; width: ${cm.display.lineNumInnerWidth}px`))
     if (markers) for (let k = 0; k < cm.options.gutters.length; ++k) {
       let id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id]
       if (found)
         gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt",
-                                   `left: ${dims.gutterLeft[id]}px; width: ${dims.gutterWidth[id]}px`))
+                                   `${side}: ${dims.gutterLeft[id]}px; width: ${dims.gutterWidth[id]}px`))
     }
   }
 }
diff --git a/src/edit/mouse_events.js b/src/edit/mouse_events.js
index 52131bc5cd..e790ff8d6e 100644
--- a/src/edit/mouse_events.js
+++ b/src/edit/mouse_events.js
@@ -278,9 +278,10 @@ function leftButtonSelect(cm, e, start, type, addNew) {
 // handlers for the corresponding event.
 function gutterEvent(cm, e, type, prevent) {
   let mX, mY
+  let check = cm.doc.direction == "ltr" ? dom => mX >= Math.floor(dom.getBoundingClientRect().right) : dom => mX <= Math.floor(dom.getBoundingClientRect().left)
   try { mX = e.clientX; mY = e.clientY }
   catch(e) { return false }
-  if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false
+  if (check(cm.display.gutters)) return false
   if (prevent) e_preventDefault(e)
 
   let display = cm.display
@@ -291,7 +292,7 @@ function gutterEvent(cm, e, type, prevent) {
 
   for (let i = 0; i < cm.options.gutters.length; ++i) {
     let g = display.gutters.childNodes[i]
-    if (g && g.getBoundingClientRect().right >= mX) {
+    if (g && check(g)) {
       let line = lineAtHeight(cm.doc, mY)
       let gutter = cm.options.gutters[i]
       signal(cm, type, cm, line, gutter, e)
diff --git a/src/edit/options.js b/src/edit/options.js
index 930c41dd21..fcedda143c 100644
--- a/src/edit/options.js
+++ b/src/edit/options.js
@@ -1,15 +1,16 @@
 import { onBlur } from "../display/focus"
 import { setGuttersForLineNumbers, updateGutters } from "../display/gutters"
-import { alignHorizontally } from "../display/line_numbers"
+import { alignHorizontally, updateFixedGutter } from "../display/line_numbers"
 import { loadMode, resetModeState } from "../display/mode_state"
 import { initScrollbars, updateScrollbars } from "../display/scrollbars"
+import { setScrollLeft } from "../display/scroll_events"
 import { updateSelection } from "../display/selection"
 import { regChange } from "../display/view_tracking"
 import { getKeyMap } from "../input/keymap"
 import { defaultSpecialCharPlaceholder } from "../line/line_data"
 import { Pos } from "../line/pos"
 import { findMaxLine } from "../line/spans"
-import { clearCaches, compensateForHScroll, estimateLineHeights } from "../measurement/position_measurement"
+import { clearCaches, estimateLineHeights } from "../measurement/position_measurement"
 import { replaceRange } from "../model/changes"
 import { mobile, windows } from "../util/browser"
 import { addClass, rmClass } from "../util/dom"
@@ -99,7 +100,7 @@ export function defineOptions(CodeMirror) {
     guttersChanged(cm)
   }, true)
   option("fixedGutter", true, (cm, val) => {
-    cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0"
+    updateFixedGutter(cm, val)
     cm.refresh()
   }, true)
   option("coverGutterNextToScrollbar", false, cm => updateScrollbars(cm), true)
@@ -153,7 +154,12 @@ export function defineOptions(CodeMirror) {
 
   option("tabindex", null, (cm, val) => cm.display.input.getField().tabIndex = val || "")
   option("autofocus", null)
-  option("direction", "ltr", (cm, val) => cm.doc.setDirection(val), true)
+  option("direction", "ltr", (cm, val) => {
+    cm.doc.setDirection(val)
+    alignHorizontally(cm)
+    setScrollLeft(cm, 0)
+    guttersChanged(cm)
+  }, true)
 }
 
 function guttersChanged(cm) {
diff --git a/src/measurement/position_measurement.js b/src/measurement/position_measurement.js
index 5fb6a6534b..c10ffcc548 100644
--- a/src/measurement/position_measurement.js
+++ b/src/measurement/position_measurement.js
@@ -419,7 +419,7 @@ export function coordsChar(cm, x, y) {
   let lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1
   if (lineN > last)
     return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, null, true, 1)
-  if (x < 0) x = 0
+  if (x < 0 && cm.doc.direction != "rtl") x = 0
 
   let lineObj = getLine(doc, lineN)
   for (;;) {
@@ -537,7 +537,7 @@ export function getDimensions(cm) {
     left[cm.options.gutters[i]] = n.offsetLeft + n.clientLeft + gutterLeft
     width[cm.options.gutters[i]] = n.clientWidth
   }
-  return {fixedPos: compensateForHScroll(d),
+  return {fixedPos: compensateForHScroll(d, cm.doc.direction == "ltr"),
           gutterTotalWidth: d.gutters.offsetWidth,
           gutterLeft: left,
           gutterWidth: width,
@@ -547,8 +547,10 @@ export function getDimensions(cm) {
 // Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
 // but using getBoundingClientRect to get a sub-pixel-accurate
 // result.
-export function compensateForHScroll(display) {
-  return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left
+export function compensateForHScroll(display, isLtr) {
+  let side = isLtr ? "left" : "right"
+  let diff = display.scroller.getBoundingClientRect()[side] - display.sizer.getBoundingClientRect()[side]
+  return isLtr ? diff : -diff
 }
 
 // Returns a function that estimates the height of a line, to use as
diff --git a/src/model/document_data.js b/src/model/document_data.js
index 7f6e3367d1..4501c2288b 100644
--- a/src/model/document_data.js
+++ b/src/model/document_data.js
@@ -100,7 +100,7 @@ export function attachDoc(cm, doc) {
 }
 
 function setDirectionClass(cm) {
-  ;(cm.doc.direction == "rtl" ? addClass : rmClass)(cm.display.lineDiv, "CodeMirror-rtl")
+  ;(cm.doc.direction == "rtl" ? addClass : rmClass)(cm.display.wrapper, "CodeMirror-rtl")
 }
 
 export function directionChanged(cm) {