diff --git a/components/style/gecko_bindings/structs_debug.rs b/components/style/gecko_bindings/structs_debug.rs
index 2fa43b82fcc..4cfdc5899ed 100644
--- a/components/style/gecko_bindings/structs_debug.rs
+++ b/components/style/gecko_bindings/structs_debug.rs
@@ -2596,17 +2596,17 @@ pub enum StyleDisplay {
     Contents = 24,
     WebkitBox = 25,
     WebkitInlineBox = 26,
-    Box = 27,
-    InlineBox = 28,
-    XulGrid = 29,
-    InlineXulGrid = 30,
-    XulGridGroup = 31,
-    XulGridLine = 32,
-    Stack = 33,
-    InlineStack = 34,
-    Deck = 35,
-    Groupbox = 36,
-    Popup = 37,
+    MozBox = 27,
+    MozInlineBox = 28,
+    MozGrid = 29,
+    MozInlineGrid = 30,
+    MozGridGroup = 31,
+    MozGridLine = 32,
+    MozStack = 33,
+    MozInlineStack = 34,
+    MozDeck = 35,
+    MozGroupbox = 36,
+    MozPopup = 37,
 }
 /**
  * A class for holding strong references to handle-managed objects.
diff --git a/components/style/gecko_bindings/structs_release.rs b/components/style/gecko_bindings/structs_release.rs
index 3d2bf88dbb7..11b1f6ea393 100644
--- a/components/style/gecko_bindings/structs_release.rs
+++ b/components/style/gecko_bindings/structs_release.rs
@@ -2570,17 +2570,17 @@ pub enum StyleDisplay {
     Contents = 24,
     WebkitBox = 25,
     WebkitInlineBox = 26,
-    Box = 27,
-    InlineBox = 28,
-    XulGrid = 29,
-    InlineXulGrid = 30,
-    XulGridGroup = 31,
-    XulGridLine = 32,
-    Stack = 33,
-    InlineStack = 34,
-    Deck = 35,
-    Groupbox = 36,
-    Popup = 37,
+    MozBox = 27,
+    MozInlineBox = 28,
+    MozGrid = 29,
+    MozInlineGrid = 30,
+    MozGridGroup = 31,
+    MozGridLine = 32,
+    MozStack = 33,
+    MozInlineStack = 34,
+    MozDeck = 35,
+    MozGroupbox = 36,
+    MozPopup = 37,
 }
 /**
  * A class for holding strong references to handle-managed objects.
diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index afddf0f4bb7..cdf4560783b 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -28,7 +28,9 @@ def to_camel_case(ident):
 class Keyword(object):
     def __init__(self, name, values, gecko_constant_prefix=None,
                  gecko_enum_prefix=None, custom_consts=None,
-                 extra_gecko_values=None, extra_servo_values=None):
+                 extra_gecko_values=None, extra_servo_values=None,
+                 gecko_strip_moz_prefix=True,
+                 gecko_inexhaustive=None):
         self.name = name
         self.values = values.split()
         if gecko_constant_prefix and gecko_enum_prefix:
@@ -39,6 +41,8 @@ class Keyword(object):
         self.extra_gecko_values = (extra_gecko_values or "").split()
         self.extra_servo_values = (extra_servo_values or "").split()
         self.consts_map = {} if custom_consts is None else custom_consts
+        self.gecko_strip_moz_prefix = gecko_strip_moz_prefix
+        self.gecko_inexhaustive = gecko_inexhaustive or (gecko_enum_prefix is None)
 
     def gecko_values(self):
         return self.values + self.extra_gecko_values
@@ -55,7 +59,7 @@ class Keyword(object):
             raise Exception("Bad product: " + product)
 
     def gecko_constant(self, value):
-        moz_stripped = value.replace("-moz-", '')
+        moz_stripped = value.replace("-moz-", '') if self.gecko_strip_moz_prefix else value
         parts = moz_stripped.split('-')
         if self.gecko_enum_prefix:
             parts = [p.title() for p in parts]
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index a9afd64c5b0..00be40d30a9 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -255,7 +255,9 @@ def set_gecko_property(ffi_name, expr):
             % for value in keyword.values_for('gecko'):
             structs::${keyword.gecko_constant(value)} => Keyword::${to_rust_ident(value)},
             % endfor
+            % if keyword.gecko_inexhaustive:
             x => panic!("Found unexpected value in style struct for ${ident} property: {:?}", x),
+            % endif
         }
     }
 </%def>
@@ -1026,8 +1028,13 @@ fn static_assert() {
     <% display_keyword = Keyword("display", "inline block inline-block table inline-table table-row-group " +
                                             "table-header-group table-footer-group table-row table-column-group " +
                                             "table-column table-cell table-caption list-item flex none " +
-                                            "-moz-box -moz-inline-box",
-                                            gecko_enum_prefix="StyleDisplay") %>
+                                            "inline-flex grid inline-grid ruby ruby-base ruby-base-container " +
+                                            "ruby-text ruby-text-container contents -webkit-box -webkit-inline-box " +
+                                            "-moz-box -moz-inline-box -moz-grid -moz-inline-grid -moz-grid-group " +
+                                            "-moz-grid-line -moz-stack -moz-inline-stack -moz-deck -moz-popup " +
+                                            "-moz-groupbox",
+                                            gecko_enum_prefix="StyleDisplay",
+                                            gecko_strip_moz_prefix=False) %>
     ${impl_keyword('display', 'mDisplay', display_keyword, True)}
 
     // overflow-y is implemented as a newtype of overflow-x, so we need special handling.
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 4fdbeda88c8..5d58fd6db5c 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -329,7 +329,7 @@
         keyword_kwargs = {a: kwargs.pop(a, None) for a in [
             'gecko_constant_prefix', 'gecko_enum_prefix',
             'extra_gecko_values', 'extra_servo_values',
-            'custom_consts',
+            'custom_consts', 'gecko_inexhaustive',
         ]}
     %>
 
diff --git a/components/style/properties/longhand/border.mako.rs b/components/style/properties/longhand/border.mako.rs
index c4ccfeb032f..0393064d532 100644
--- a/components/style/properties/longhand/border.mako.rs
+++ b/components/style/properties/longhand/border.mako.rs
@@ -58,11 +58,13 @@
 
 ${helpers.single_keyword("box-decoration-break", "slice clone",
                          gecko_enum_prefix="StyleBoxDecorationBreak",
+                         gecko_inexhaustive=True,
                          products="gecko", animatable=False)}
 
 ${helpers.single_keyword("-moz-float-edge", "content-box margin-box",
                          gecko_ffi_name="mFloatEdge",
                          gecko_enum_prefix="StyleFloatEdge",
+                         gecko_inexhaustive=True,
                          products="gecko",
                          animatable=False)}
 
diff --git a/components/style/properties/longhand/box.mako.rs b/components/style/properties/longhand/box.mako.rs
index c48d4948376..818ed9316e1 100644
--- a/components/style/properties/longhand/box.mako.rs
+++ b/components/style/properties/longhand/box.mako.rs
@@ -22,7 +22,11 @@
             none
         """.split()
         if product == "gecko":
-            values += "-moz-box -moz-inline-box".split()
+            values += """inline-flex grid inline-grid ruby ruby-base ruby-base-container
+                ruby-text ruby-text-container contents -webkit-box -webkit-inline-box
+                -moz-box -moz-inline-box -moz-grid -moz-inline-grid -moz-grid-group
+                -moz-grid-line -moz-stack -moz-inline-stack -moz-deck -moz-popup
+                -moz-groupbox""".split()
     %>
     pub use self::computed_value::T as SpecifiedValue;
     use values::computed::ComputedValueAsSpecified;
@@ -92,6 +96,7 @@ ${helpers.single_keyword("position", "static absolute relative fixed",
                                   animatable="False"
                                   need_clone="True"
                                   gecko_enum_prefix="StyleFloat"
+                                  gecko_inexhaustive="True"
                                   gecko_ffi_name="mFloat">
     use values::NoViewportPercentage;
     impl NoViewportPercentage for SpecifiedValue {}
diff --git a/components/style/properties/longhand/inherited_svg.mako.rs b/components/style/properties/longhand/inherited_svg.mako.rs
index 8bff77f9c37..6a0b00eced9 100644
--- a/components/style/properties/longhand/inherited_svg.mako.rs
+++ b/components/style/properties/longhand/inherited_svg.mako.rs
@@ -35,6 +35,7 @@ ${helpers.predefined_type("fill-opacity", "Opacity", "1.0",
 
 ${helpers.single_keyword("fill-rule", "nonzero evenodd",
                          gecko_enum_prefix="StyleFillRule",
+                         gecko_inexhaustive=True,
                          products="gecko", animatable=False)}
 
 ${helpers.single_keyword("shape-rendering",
@@ -60,4 +61,5 @@ ${helpers.predefined_type("stroke-opacity", "Opacity", "1.0",
 ${helpers.single_keyword("clip-rule", "nonzero evenodd",
                          products="gecko",
                          gecko_enum_prefix="StyleFillRule",
+                         gecko_inexhaustive=True,
                          animatable=False)}
diff --git a/components/style/properties/longhand/pointing.mako.rs b/components/style/properties/longhand/pointing.mako.rs
index d5306f376a9..412e2fe080c 100644
--- a/components/style/properties/longhand/pointing.mako.rs
+++ b/components/style/properties/longhand/pointing.mako.rs
@@ -151,15 +151,18 @@ ${helpers.single_keyword("pointer-events", "auto none", animatable=False)}
 ${helpers.single_keyword("-moz-user-input", "none enabled disabled",
                          products="gecko", gecko_ffi_name="mUserInput",
                          gecko_enum_prefix="StyleUserInput",
+                         gecko_inexhaustive=True,
                          animatable=False)}
 
 ${helpers.single_keyword("-moz-user-modify", "read-only read-write write-only",
                          products="gecko", gecko_ffi_name="mUserModify",
                          gecko_enum_prefix="StyleUserModify",
+                         gecko_inexhaustive=True,
                          animatable=False)}
 
 ${helpers.single_keyword("-moz-user-focus",
                          "ignore normal select-after select-before select-menu select-same select-all none",
                          products="gecko", gecko_ffi_name="mUserFocus",
                          gecko_enum_prefix="StyleUserFocus",
+                         gecko_inexhaustive=True,
                          animatable=False)}
diff --git a/components/style/properties/longhand/ui.mako.rs b/components/style/properties/longhand/ui.mako.rs
index f815c1d8518..cd537677f6f 100644
--- a/components/style/properties/longhand/ui.mako.rs
+++ b/components/style/properties/longhand/ui.mako.rs
@@ -16,4 +16,5 @@ ${helpers.single_keyword("ime-mode", "normal auto active disabled inactive",
 ${helpers.single_keyword("-moz-user-select", "auto text none all", products="gecko",
                          gecko_ffi_name="mUserSelect",
                          gecko_enum_prefix="StyleUserSelect",
+                         gecko_inexhaustive=True,
                          animatable=False)}
diff --git a/components/style/properties/longhand/xul.mako.rs b/components/style/properties/longhand/xul.mako.rs
index 23c1da1246b..bc64308a115 100644
--- a/components/style/properties/longhand/xul.mako.rs
+++ b/components/style/properties/longhand/xul.mako.rs
@@ -11,6 +11,7 @@
 ${helpers.single_keyword("-moz-box-align", "stretch start center baseline end",
                          products="gecko", gecko_ffi_name="mBoxAlign",
                          gecko_enum_prefix="StyleBoxAlign",
+                         gecko_inexhaustive=True,
                          animatable=False)}
 
 ${helpers.predefined_type("-moz-box-flex", "Number", "0.0", "parse_non_negative",