--- a/devtools/client/sourceeditor/test/css_autocompletion_tests.json
+++ b/devtools/client/sourceeditor/test/css_autocompletion_tests.json
@@ -20,17 +20,17 @@
                "-moz-appearance"]],
     [[12, 20], ["none", "number-input"]],
     [[12, 22], ["none"]],
     [[17, 22], ["hsl", "hsla"]],
     [[19, 10], ["background", "background-attachment", "background-blend-mode",
                 "background-clip", "background-color", "background-image",
                 "background-origin", "background-position", "background-position-x",
                 "background-position-y", "background-repeat", "background-size"]],
-    [[21,  9], ["-moz-calc", "auto", "calc", "inherit", "initial","unset"]],
+    [[21,  9], ["auto", "calc", "inherit", "initial","unset"]],
     [[25, 26], [".devtools-toolbarbutton > tab",
                 ".devtools-toolbarbutton > hbox",
                 ".devtools-toolbarbutton > .toolbarbutton-menubutton-button"]],
     [[25, 31], [".devtools-toolbarbutton > hbox.toolbarbutton-menubutton-button"]],
     [[29, 20], [".devtools-menulist:after", ".devtools-menulist:active"]],
     [[30, 10], ["#devtools-anotherone", "#devtools-itjustgoeson", "#devtools-menu",
                 "#devtools-okstopitnow", "#devtools-toolbarbutton", "#devtools-yetagain"]],
     [[39, 39], [".devtools-toolbarbutton:not([label]) > tab"]],

--- a/devtools/server/tests/mochitest/test_css-properties.html
+++ b/devtools/server/tests/mochitest/test_css-properties.html
@@ -77,17 +77,17 @@ window.onload = function() {
     ok(cssProperties.isKnown("--foob\\{ar"),
       "A CSS variable with escaped character properly evaluates.");
     ok(cssProperties.isKnown("--fübar"),
       "A CSS variable unicode properly evaluates.");
     ok(!cssProperties.isKnown("--foo bar"),
       "A CSS variable with spaces fails");
 
     is(toSortedString(cssProperties.getValues('margin')),
-       toSortedString(["-moz-calc","auto","calc","inherit","initial","unset"]),
+       toSortedString(["auto","calc","inherit","initial","unset"]),
        "Can get values for the CSS margin.");
     is(cssProperties.getValues('foobar').length, 0,
       "Unknown values return an empty array.");
 
     const bgColorValues = cssProperties.getValues('background-color');
     ok(bgColorValues.includes("blanchedalmond"),
       "A property with color values includes blanchedalmond.");
     ok(bgColorValues.includes("papayawhip"),