diff --git a/rescript.json b/rescript.json
index eaf0b5f6..48cfb109 100644
--- a/rescript.json
+++ b/rescript.json
@@ -19,6 +19,11 @@
     "WebAPI.Media": ["WebAPI.HTML", "Media"],
     "WebAPI.WebAudio": ["WebAPI.Media", "WebAPI.Messaging", "WebAudio"],
     "WebAPI.SVG": ["WebAPI.DOMNodes", "WebAPI.Geometry", "SVG"],
+    "WebAPI.Observers": [
+      "WebAPI.DOMNodes",
+      "WebAPI.Geometry",
+      "Observers"
+    ],
     "WebAPI.File": ["WebAPI.Event", "File"],
     "WebAPI.URL": ["WebAPI.DOM", "URL"],
     "WebAPI.Fetch": ["WebAPI.Event", "WebAPI.File", "WebAPI.URL", "Fetch"],
@@ -361,12 +366,14 @@
       ]
     },
     {
-      "dir": "src/IntersectionObserver",
+      "dir": "src/observers",
       "subdirs": true,
-      "feature": "WebAPI.IntersectionObserver",
+      "feature": "Observers",
       "public": [
         "IntersectionObserver",
-        "IntersectionObserverRoot"
+        "IntersectionObserverRoot",
+        "MutationObserver",
+        "ResizeObserver"
       ]
     },
     {
@@ -402,14 +409,6 @@
         "VideoPlaybackQuality"
       ]
     },
-    {
-      "dir": "src/MutationObserver",
-      "subdirs": true,
-      "feature": "WebAPI.MutationObserver",
-      "public": [
-        "MutationObserver"
-      ]
-    },
     {
       "dir": "src/performance",
       "subdirs": true,
@@ -428,14 +427,6 @@
         "Permissions"
       ]
     },
-    {
-      "dir": "src/ResizeObserver",
-      "subdirs": true,
-      "feature": "WebAPI.ResizeObserver",
-      "public": [
-        "ResizeObserver"
-      ]
-    },
     {
       "dir": "src/ServiceWorker",
       "subdirs": true,
diff --git a/src/IntersectionObserver/IntersectionObserver.res b/src/observers/IntersectionObserver.res
similarity index 100%
rename from src/IntersectionObserver/IntersectionObserver.res
rename to src/observers/IntersectionObserver.res
diff --git a/src/IntersectionObserver/IntersectionObserverRoot.res b/src/observers/IntersectionObserverRoot.res
similarity index 87%
rename from src/IntersectionObserver/IntersectionObserverRoot.res
rename to src/observers/IntersectionObserverRoot.res
index ea99dd53..1d5c88f7 100644
--- a/src/IntersectionObserver/IntersectionObserverRoot.res
+++ b/src/observers/IntersectionObserverRoot.res
@@ -10,10 +10,12 @@ type decoded =
   | Document(DOM.document)
   | Null
 
+let isDocument = (_: 't): bool => %raw(`param instanceof Document`)
+
 let decode = (t: IntersectionObserverTypes.root): decoded => {
   if Element.isInstanceOf(t) {
     Element(t->toElement)
-  } else if Document.isInstanceOf(t) {
+  } else if isDocument(t) {
     Document(t->toDocument)
   } else {
     Null
diff --git a/src/IntersectionObserver/IntersectionObserverTypes.res b/src/observers/IntersectionObserverTypes.res
similarity index 100%
rename from src/IntersectionObserver/IntersectionObserverTypes.res
rename to src/observers/IntersectionObserverTypes.res
diff --git a/src/MutationObserver/MutationObserver.res b/src/observers/MutationObserver.res
similarity index 100%
rename from src/MutationObserver/MutationObserver.res
rename to src/observers/MutationObserver.res
diff --git a/src/ResizeObserver/ResizeObserver.res b/src/observers/ResizeObserver.res
similarity index 100%
rename from src/ResizeObserver/ResizeObserver.res
rename to src/observers/ResizeObserver.res
diff --git a/src/ResizeObserver/ResizeObserverTypes.res b/src/observers/ResizeObserverTypes.res
similarity index 100%
rename from src/ResizeObserver/ResizeObserverTypes.res
rename to src/observers/ResizeObserverTypes.res