diff --git a/weasyprint/layout/flex.py b/weasyprint/layout/flex.py
index 3d610a50f..7a6579321 100644
--- a/weasyprint/layout/flex.py
+++ b/weasyprint/layout/flex.py
@@ -593,7 +593,6 @@ def flex_layout(context, box, max_position_y, skip_stack, containing_block,
             # else: Cross size has been set by step 7
 
     # Step 12
-    # TODO: handle rtl
     original_position_axis = (
         box.content_box_x() if axis == 'width'
         else box.content_box_y())
@@ -650,33 +649,62 @@ def flex_layout(context, box, max_position_y, skip_stack, containing_block,
                         child.margin_bottom = free_space
             free_space = 0
 
-        if justify_content == 'flex-end':
-            position_axis += free_space
-        elif justify_content == 'center':
-            position_axis += free_space / 2
-        elif justify_content == 'space-around':
-            position_axis += free_space / len(line) / 2
-        elif justify_content == 'space-evenly':
-            position_axis += free_space / (len(line) + 1)
+        if (box.style['direction'] == 'rtl' and
+                box.style['flex_direction'].startswith('row')):
+            if justify_content == 'flex-end':
+                position_axis -= free_space
+            elif justify_content == 'center':
+                position_axis -= free_space / 2
+            elif justify_content == 'space-around':
+                position_axis -= free_space / len(line) / 2
+            elif justify_content == 'space-evenly':
+                position_axis -= free_space / (len(line) - 1)
 
-        for i, child in line:
-            if axis == 'width':
-                child.position_x = position_axis
-                if justify_content == 'stretch':
-                    child.width += free_space / len(line)
-            else:
-                child.position_y = position_axis
-            position_axis += (
-                child.margin_width() if axis == 'width'
-                else child.margin_height())
-            if justify_content == 'space-around':
-                position_axis += free_space / len(line)
-            elif justify_content == 'space-between':
-                if len(line) > 1:
-                    position_axis += free_space / (len(line) - 1)
+            for i, child in line:
+                if axis == 'width':
+                    child.position_x = position_axis
+                    if justify_content == 'stretch':
+                        child.width -= free_space / len(line)
+                else:
+                    child.position_y = position_axis
+                position_axis -= (
+                    child.margin_width() if axis == 'width'
+                    else child.margin_height())
+                if justify_content == 'space-around':
+                    position_axis -= free_space / len(line)
+                elif justify_content == 'space-between':
+                    if len(line) > 1:
+                        position_axis -= free_space / (len(line) + 1)
+                elif justify_content == 'space-evenly':
+                    position_axis -= free_space / (len(line) - 1)
+        else:
+            if justify_content == 'flex-end':
+                position_axis += free_space
+            elif justify_content == 'center':
+                position_axis += free_space / 2
+            elif justify_content == 'space-around':
+                position_axis += free_space / len(line) / 2
             elif justify_content == 'space-evenly':
                 position_axis += free_space / (len(line) + 1)
 
+            for i, child in line:
+                if axis == 'width':
+                    child.position_x = position_axis
+                    if justify_content == 'stretch':
+                        child.width += free_space / len(line)
+                else:
+                    child.position_y = position_axis
+                position_axis += (
+                    child.margin_width() if axis == 'width'
+                    else child.margin_height())
+                if justify_content == 'space-around':
+                    position_axis += free_space / len(line)
+                elif justify_content == 'space-between':
+                    if len(line) > 1:
+                        position_axis += free_space / (len(line) - 1)
+                elif justify_content == 'space-evenly':
+                    position_axis += free_space / (len(line) + 1)
+
     # Step 13
     position_cross = (
         box.content_box_y() if cross == 'height'
diff --git a/weasyprint/tests/test_layout/test_flex.py b/weasyprint/tests/test_layout/test_flex.py
index e0c3be1cd..18e75bc5b 100644
--- a/weasyprint/tests/test_layout/test_flex.py
+++ b/weasyprint/tests/test_layout/test_flex.py
@@ -37,6 +37,33 @@ def test_flex_direction_row():
     assert div_1.position_x < div_2.position_x < div_3.position_x
 
 
+@assert_no_logs
+def test_flex_direction_row_rtl():
+    page, = render_pages('''
+      <article style="display: flex; direction: rtl">
+        <div>A</div>
+        <div>B</div>
+        <div>C</div>
+      </article>
+    ''')
+    html, = page.children
+    body, = html.children
+    article, = body.children
+    div_1, div_2, div_3 = article.children
+    assert div_1.children[0].children[0].text == 'A'
+    assert div_2.children[0].children[0].text == 'B'
+    assert div_3.children[0].children[0].text == 'C'
+    assert (
+        div_1.position_y ==
+        div_2.position_y ==
+        div_3.position_y ==
+        article.position_y)
+    assert (
+        div_1.position_x + div_1.width ==
+        article.position_x + article.width)
+    assert div_1.position_x > div_2.position_x > div_3.position_x
+
+
 @assert_no_logs
 def test_flex_direction_row_reverse():
     page, = render_pages('''
@@ -64,6 +91,32 @@ def test_flex_direction_row_reverse():
     assert div_1.position_x < div_2.position_x < div_3.position_x
 
 
+@assert_no_logs
+def test_flex_direction_row_reverse_rtl():
+    page, = render_pages('''
+      <article style="display: flex; flex-direction: row-reverse;
+      direction: rtl">
+        <div>A</div>
+        <div>B</div>
+        <div>C</div>
+      </article>
+    ''')
+    html, = page.children
+    body, = html.children
+    article, = body.children
+    div_1, div_2, div_3 = article.children
+    assert div_1.children[0].children[0].text == 'C'
+    assert div_2.children[0].children[0].text == 'B'
+    assert div_3.children[0].children[0].text == 'A'
+    assert (
+        div_1.position_y ==
+        div_2.position_y ==
+        div_3.position_y ==
+        article.position_y)
+    assert div_3.position_x == article.position_x
+    assert div_1.position_x > div_2.position_x > div_3.position_x
+
+
 @assert_no_logs
 def test_flex_direction_column():
     page, = render_pages('''
@@ -89,6 +142,32 @@ def test_flex_direction_column():
     assert div_1.position_y < div_2.position_y < div_3.position_y
 
 
+@assert_no_logs
+def test_flex_direction_column_rtl():
+    page, = render_pages('''
+      <article style="display: flex; flex-direction: column;
+      direction: rtl">
+        <div>A</div>
+        <div>B</div>
+        <div>C</div>
+      </article>
+    ''')
+    html, = page.children
+    body, = html.children
+    article, = body.children
+    div_1, div_2, div_3 = article.children
+    assert div_1.children[0].children[0].text == 'A'
+    assert div_2.children[0].children[0].text == 'B'
+    assert div_3.children[0].children[0].text == 'C'
+    assert (
+        div_1.position_x ==
+        div_2.position_x ==
+        div_3.position_x ==
+        article.position_x)
+    assert div_1.position_y == article.position_y
+    assert div_1.position_y < div_2.position_y < div_3.position_y
+
+
 @assert_no_logs
 def test_flex_direction_column_reverse():
     page, = render_pages('''
@@ -116,6 +195,34 @@ def test_flex_direction_column_reverse():
     assert div_1.position_y < div_2.position_y < div_3.position_y
 
 
+@assert_no_logs
+def test_flex_direction_column_reverse_rtl():
+    page, = render_pages('''
+      <article style="display: flex; flex-direction: column-reverse;
+      direction: rtl">
+        <div>A</div>
+        <div>B</div>
+        <div>C</div>
+      </article>
+    ''')
+    html, = page.children
+    body, = html.children
+    article, = body.children
+    div_1, div_2, div_3 = article.children
+    assert div_1.children[0].children[0].text == 'C'
+    assert div_2.children[0].children[0].text == 'B'
+    assert div_3.children[0].children[0].text == 'A'
+    assert (
+        div_1.position_x ==
+        div_2.position_x ==
+        div_3.position_x ==
+        article.position_x)
+    assert (
+        div_3.position_y + div_3.height ==
+        article.position_y + article.height)
+    assert div_1.position_y < div_2.position_y < div_3.position_y
+
+
 @assert_no_logs
 def test_flex_row_wrap():
     page, = render_pages('''