diff --git a/layout/reftests/scrolling/reftest.list b/layout/reftests/scrolling/reftest.list
index b2efe5e0d1e1..0db7f1b65fa7 100644
--- a/layout/reftests/scrolling/reftest.list
+++ b/layout/reftests/scrolling/reftest.list
@@ -16,6 +16,8 @@ skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.s
 skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.scroll-behavior.property-enabled,true) == scroll-behavior-5.html scroll-behavior-5.html?ref # see bug 1041833
 skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.scroll-behavior.property-enabled,true) == scroll-behavior-6.html scroll-behavior-6.html?ref # see bug 1041833
 skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.scroll-behavior.property-enabled,true) == scroll-behavior-7.html scroll-behavior-7.html?ref # see bug 1041833
+skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.scroll-behavior.property-enabled,true) == scroll-behavior-8.html scroll-behavior-8.html?ref # see bug 1041833
+skip-if(Android) pref(layout.css.scroll-behavior.enabled,true) pref(layout.css.scroll-behavior.property-enabled,true) == scroll-behavior-9.html scroll-behavior-9.html?ref # see bug 1041833
 skip-if(B2G&&browserIsRemote) HTTP == simple-1.html simple-1.html?ref
 skip-if(B2G) HTTP == subpixel-1.html#d subpixel-1-ref.html#d
 fuzzy-if(Android,4,120) HTTP == text-1.html text-1.html?ref
diff --git a/layout/reftests/scrolling/scroll-behavior-8.html b/layout/reftests/scrolling/scroll-behavior-8.html
new file mode 100644
index 000000000000..437d441b3957
--- /dev/null
+++ b/layout/reftests/scrolling/scroll-behavior-8.html
@@ -0,0 +1,97 @@
+<!DOCTYPE HTML>
+<html class="reftest-wait">
+<head>
+    <meta charset="utf-8">
+    <title>Testcase for bug 1010538 - Dynamically change scroll-behavior</title>
+    <style type="text/css">
+
+        html,body {
+            color: black;
+            background-color: white;
+            font-size: 16px;
+            padding: 0;
+            margin: 0;
+        }
+
+        .a_box {
+            position: relative;
+            left: 0px;
+            top: 0px;
+            width: 20px;
+            height: 20px;
+            background: blue;
+        }
+
+        .another_box {
+            position: relative;
+            left: 2000px;
+            top: 2000px;
+            width: 20px;
+            height: 20px;
+            background: green;
+        }
+
+        .scroll_box {
+            width: 50px;
+            height: 50px;
+            overflow: scroll;
+        }
+
+        #scroll_2 {
+            scroll-behavior: auto;
+        }
+
+        #scroll_3 {
+            scroll-behavior: smooth;
+        }
+
+    </style>
+</head>
+<body>
+  <div id="scroll_1" class="scroll_box">
+    <div id="box1a" class="a_box"></div>
+    <div id="box1b" class="another_box"></div>
+  </div>
+  <div id="scroll_2" class="scroll_box">
+    <div id="box2a" class="a_box"></div>
+    <div id="box2b" class="another_box"></div>
+  </div>
+  <div id="scroll_3" class="scroll_box">
+    <div id="box3a" class="a_box"></div>
+    <div id="box3b" class="another_box"></div>
+  </div>
+<script>
+  function doTest() {
+    if (document.location.search != '?ref') {
+      // Expect smooth scroll:
+      document.getElementById("scroll_1").style.scrollBehavior = "smooth";
+      document.getElementById("scroll_1").scrollTo({left: 0, top: 0});
+      document.getElementById("scroll_2").style.scrollBehavior = "smooth";
+      document.getElementById("scroll_2").scrollTo({left: 0, top: 0});
+
+      // Expect instant scroll:
+      document.getElementById("scroll_3").style.scrollBehavior = "auto";
+      document.getElementById("scroll_3").scrollTo({left: 0, top: 0});
+    } else {
+      document.getElementById("scroll_1").scrollTo({left: 0, top: 0, behavior: "smooth"});
+      document.getElementById("scroll_2").scrollTo({left: 0, top: 0, behavior: "smooth"});
+      document.getElementById("scroll_3").scrollTo({left: 0, top: 0, behavior: "instant"});
+    }
+
+    // Interrupt any smooth scrolling
+    for (var i=1; i <= 3; i++) {
+      document.getElementById("scroll_" + i).scrollTo();
+    }
+
+    document.documentElement.removeAttribute("class");
+  }
+
+  for (var i=1; i <= 3; i++) {
+    document.getElementById("box" + i + "b")
+      .scrollIntoView({block: "start", behavior: "instant"});
+  }
+
+  window.addEventListener("MozReftestInvalidate", doTest, false);
+</script>
+</body>
+</html>
diff --git a/layout/reftests/scrolling/scroll-behavior-9.html b/layout/reftests/scrolling/scroll-behavior-9.html
new file mode 100644
index 000000000000..b4f937b5aa73
--- /dev/null
+++ b/layout/reftests/scrolling/scroll-behavior-9.html
@@ -0,0 +1,55 @@
+<!DOCTYPE HTML>
+<html class="reftest-wait">
+<head>
+    <meta charset="utf-8">
+    <title>Testcase for bug 1082098, smooth scrolling expected after dynamically setting scroll-behavior on body</title>
+    <style type="text/css">
+
+        html,body {
+            color: black;
+            background-color: white;
+            font-size: 16px;
+            padding: 0;
+            margin: 0;
+        }
+
+        #a_box {
+            position: relative;
+            left: 10px;
+            top: 10px;
+            width: 20px;
+            height: 20px;
+            background: blue;
+        }
+
+        #another_box {
+            position: relative;
+            left: 2000px;
+            top: 2000px;
+            width: 20px;
+            height: 20px;
+            background: green;
+        }
+
+    </style>
+</head>
+<body>
+  <div id="a_box"></div>
+  <div id="another_box"></div>
+<script>
+  function doTest() {
+    if (document.location.search != '?ref') {
+      // Scroll - expected to be smooth
+      window.scrollTo({left: 500, top: 500});
+      // Interrupt smooth scrolling
+      window.scrollTo({left: window.scrollX, top: window.scrollY});
+      // If scroll was not performed smoothly, we would be at 500,500 now
+    }
+    document.documentElement.removeAttribute("class");
+  }
+  window.scrollTo({left: 0, top: 0, behavior: "instant"});
+  document.body.style.scrollBehavior = "smooth";
+  window.addEventListener("MozReftestInvalidate", doTest, false);
+</script>
+</body>
+</html>
