diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 7f97868a378..0ad87747a12 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -4938,8 +4938,6 @@ class CGDOMJSProxyHandler_defineProperty(CGAbstractExternMethod):
             set += ("if RUST_JSID_IS_STRING(id) {\n" +
                     CGIndenter(CGProxyNamedSetter(self.descriptor)).define() +
                     "    return (*opresult).succeed();\n" +
-                    "} else {\n" +
-                    "    return false;\n" +
                     "}\n")
         else:
             set += ("if RUST_JSID_IS_STRING(id) {\n" +
@@ -4948,7 +4946,7 @@ class CGDOMJSProxyHandler_defineProperty(CGAbstractExternMethod):
                     "        return (*opresult).failNoNamedSetter();\n"
                     "    }\n"
                     "}\n")
-            set += "return proxyhandler::define_property(%s);" % ", ".join(a.name for a in self.args)
+        set += "return proxyhandler::define_property(%s);" % ", ".join(a.name for a in self.args)
         return set
 
     def definition_body(self):
diff --git a/components/script/dom/bindings/conversions.rs b/components/script/dom/bindings/conversions.rs
index 9afae9f6804..6ae233aa034 100644
--- a/components/script/dom/bindings/conversions.rs
+++ b/components/script/dom/bindings/conversions.rs
@@ -84,13 +84,13 @@ impl<T: Float + FromJSValConvertible<Config=()>> FromJSValConvertible for Finite
                          value: HandleValue,
                          option: ())
                          -> Result<ConversionResult<Finite<T>>, ()> {
-        let result = match FromJSValConvertible::from_jsval(cx, value, option) {
-            Ok(ConversionResult::Success(v)) => v,
-            Ok(ConversionResult::Failure(error)) => {
+        let result = match FromJSValConvertible::from_jsval(cx, value, option)? {
+            ConversionResult::Success(v) => v,
+            ConversionResult::Failure(error) => {
+                // FIXME(emilio): Why throwing instead of propagating the error?
                 throw_type_error(cx, &error);
                 return Err(());
             }
-            _ => return Err(()),
         };
         match Finite::new(result) {
             Some(v) => Ok(ConversionResult::Success(v)),
diff --git a/components/script/dom/bindings/utils.rs b/components/script/dom/bindings/utils.rs
index 1c4682225b0..4a343cbb115 100644
--- a/components/script/dom/bindings/utils.rs
+++ b/components/script/dom/bindings/utils.rs
@@ -414,18 +414,22 @@ unsafe fn generic_call(cx: *mut JSContext,
                                               -> bool)
                        -> bool {
     let args = CallArgs::from_vp(vp, argc);
+
+    let info = RUST_FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));
+    let proto_id = (*info).protoID;
+
     let thisobj = args.thisv();
     if !thisobj.get().is_null_or_undefined() && !thisobj.get().is_object() {
+        throw_invalid_this(cx, proto_id);
         return false;
     }
+
     let obj = if thisobj.get().is_object() {
         thisobj.get().to_object()
     } else {
         GetGlobalForObjectCrossCompartment(JS_CALLEE(cx, vp).to_object_or_null())
     };
     rooted!(in(cx) let obj = obj);
-    let info = RUST_FUNCTION_VALUE_TO_JITINFO(JS_CALLEE(cx, vp));
-    let proto_id = (*info).protoID;
     let depth = (*info).depth;
     let proto_check = |class: &'static DOMClass| {
         class.interface_chain[depth as usize] as u16 == proto_id
diff --git a/tests/wpt/metadata/webstorage/storage_setitem.html.ini b/tests/wpt/metadata/webstorage/storage_setitem.html.ini
index 0a0f43019b2..ca08ab7a750 100644
--- a/tests/wpt/metadata/webstorage/storage_setitem.html.ini
+++ b/tests/wpt/metadata/webstorage/storage_setitem.html.ini
@@ -1,6 +1,5 @@
 [storage_setitem.html]
   type: testharness
-  expected: TIMEOUT
   [localStorage[\] = "�"]
     expected: FAIL
     bug: https://github.com/servo/servo/issues/6564
@@ -14,6 +13,72 @@
     bug: https://github.com/servo/servo/issues/6564
 
   [localStorage["0"\]]
-    expected: TIMEOUT
+    expected: FAIL
     bug: https://github.com/servo/servo/issues/10686
 
+  [localStorage["1"\]]
+    expected: FAIL
+
+  [localStorage["2"\]]
+    expected: FAIL
+
+  [localStorage["3"\]]
+    expected: FAIL
+
+  [localStorage["4"\]]
+    expected: FAIL
+
+  [localStorage["5"\]]
+    expected: FAIL
+
+  [localStorage["6"\]]
+    expected: FAIL
+
+  [localStorage["7"\]]
+    expected: FAIL
+
+  [localStorage["8"\]]
+    expected: FAIL
+
+  [localStorage["9"\]]
+    expected: FAIL
+
+  [sessionStorage[\] = "�"]
+    expected: FAIL
+
+  [sessionStorage[\] = "�a"]
+    expected: FAIL
+
+  [sessionStorage[\] = "a�"]
+    expected: FAIL
+
+  [sessionStorage["0"\]]
+    expected: FAIL
+
+  [sessionStorage["1"\]]
+    expected: FAIL
+
+  [sessionStorage["2"\]]
+    expected: FAIL
+
+  [sessionStorage["3"\]]
+    expected: FAIL
+
+  [sessionStorage["4"\]]
+    expected: FAIL
+
+  [sessionStorage["5"\]]
+    expected: FAIL
+
+  [sessionStorage["6"\]]
+    expected: FAIL
+
+  [sessionStorage["7"\]]
+    expected: FAIL
+
+  [sessionStorage["8"\]]
+    expected: FAIL
+
+  [sessionStorage["9"\]]
+    expected: FAIL
+
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index f400c7abdef..a451a31a9c2 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -14739,6 +14739,12 @@
      {}
     ]
    ],
+   "mozilla/invalid-this.html": [
+    [
+     "/_mozilla/mozilla/invalid-this.html",
+     {}
+    ]
+   ],
    "mozilla/iterable.html": [
     [
      "/_mozilla/mozilla/iterable.html",
@@ -28074,6 +28080,10 @@
    "c9dcc4f24540914b3be1ef18f13b721773eb76be",
    "testharness"
   ],
+  "mozilla/invalid-this.html": [
+   "4ed18511e6399b356fe196b92f72dd16a9019f55",
+   "testharness"
+  ],
   "mozilla/iterable.html": [
    "66f05b1f12b8be392705f5ba4a96c70b9226721d",
    "testharness"
diff --git a/tests/wpt/mozilla/meta/css/css-position-3/position-sticky-nested-bottom.html.ini b/tests/wpt/mozilla/meta/css/css-position-3/position-sticky-nested-bottom.html.ini
index 54aa5d5dac5..796caade081 100644
--- a/tests/wpt/mozilla/meta/css/css-position-3/position-sticky-nested-bottom.html.ini
+++ b/tests/wpt/mozilla/meta/css/css-position-3/position-sticky-nested-bottom.html.ini
@@ -5,4 +5,3 @@
   [Untitled]
     expected: FAIL
 
-
diff --git a/tests/wpt/mozilla/tests/mozilla/invalid-this.html b/tests/wpt/mozilla/tests/mozilla/invalid-this.html
new file mode 100644
index 00000000000..bc1e3505226
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/invalid-this.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Test for #18535: Wrong type arguments to some JS functions abort the execution of the script.</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+test(function() {
+  assert_throws(new TypeError(), function() { window.atob.call("", localStorage); })
+  assert_throws(new TypeError(), function() { window.removeEventListener.call("", ""); })
+  assert_throws(new TypeError(), function() { window.alert.call(""); })
+  assert_throws(new TypeError(), function() { window.moveTo.call(128); })
+})
+</script>