diff --git a/components/style/properties/longhand/outline.mako.rs b/components/style/properties/longhand/outline.mako.rs
index 2eab90ce556..afa2c9a06c7 100644
--- a/components/style/properties/longhand/outline.mako.rs
+++ b/components/style/properties/longhand/outline.mako.rs
@@ -58,4 +58,11 @@ ${helpers.predefined_type("outline-color", "CSSColor", "::cssparser::Color::Curr
     }
 </%helpers:longhand>
 
+// The -moz-outline-radius-* properties are non-standard and not on a standards track.
+% for corner in ["topleft", "topright", "bottomright", "bottomleft"]:
+    ${helpers.predefined_type("-moz-outline-radius-" + corner, "BorderRadiusSize",
+                              "computed::BorderRadiusSize::zero()",
+                              "parse", products="gecko")}
+% endfor
+
 ${helpers.predefined_type("outline-offset", "Length", "Au(0)")}
diff --git a/ports/geckolib/properties.mako.rs b/ports/geckolib/properties.mako.rs
index c0cee275eb9..4037ea58fe1 100644
--- a/ports/geckolib/properties.mako.rs
+++ b/ports/geckolib/properties.mako.rs
@@ -548,14 +548,25 @@ fn static_assert() {
     % endfor
 </%self:impl_trait>
 
+<% skip_outline_longhands = " ".join("outline-color outline-style".split() +
+                                     ["-moz-outline-radius-{0}".format(x.ident.replace("_", ""))
+                                      for x in CORNERS]) %>
 <%self:impl_trait style_struct_name="Outline"
-                  skip_longhands="outline-color outline-style"
+                  skip_longhands="${skip_outline_longhands}"
                   skip_additionals="*">
 
     <% impl_keyword("outline_style", "mOutlineStyle", border_style_keyword, need_clone=True) %>
 
     <% impl_color("outline_color", "mOutlineColor", color_flags_ffi_name="mOutlineStyle") %>
 
+    % for corner in CORNERS:
+    <% impl_corner_style_coord("_moz_outline_radius_%s" % corner.ident.replace("_", ""),
+                               "mOutlineRadius.mUnits[%s]" % corner.x_index,
+                               "mOutlineRadius.mValues[%s]" % corner.x_index,
+                               "mOutlineRadius.mUnits[%s]" % corner.y_index,
+                               "mOutlineRadius.mValues[%s]" % corner.y_index) %>
+    % endfor
+
     fn outline_has_nonzero_width(&self) -> bool {
         self.gecko.mCachedOutlineWidth != 0
     }