diff --git a/src/position-observer.js b/src/position-observer.js
index 9b52181..3f2f06b 100644
--- a/src/position-observer.js
+++ b/src/position-observer.js
@@ -49,18 +49,20 @@ PositionObserver.prototype.check = function(viewportState) {
 
   let untriggered = false
 
-  if (onBottom && !_wasBottom && atBottom) onBottom.call(this, container, viewportState)
-  else if (onTop && !_wasTop && atTop) onTop.call(this, container, viewportState)
-  else if (onRight && !_wasRight && atRight) onRight.call(this, container, viewportState)
-  else if (onLeft && !_wasLeft && atLeft) onLeft.call(this, container, viewportState)
-  else if (onFit && !_wasFit && fits) onFit.call(this, container, viewportState)
-  else untriggered = true
+  try {
+    if (onBottom && !_wasBottom && atBottom) onBottom.call(this, container, viewportState)
+    else if (onTop && !_wasTop && atTop) onTop.call(this, container, viewportState)
+    else if (onRight && !_wasRight && atRight) onRight.call(this, container, viewportState)
+    else if (onLeft && !_wasLeft && atLeft) onLeft.call(this, container, viewportState)
+    else if (onFit && !_wasFit && fits) onFit.call(this, container, viewportState)
+    else untriggered = true
 
-  if (once && !untriggered) this.destroy()
-
-  this._wasTop = atTop
-  this._wasBottom = atBottom
-  this._wasLeft = atLeft
-  this._wasRight = atRight
-  this._wasFit = fits
+    if (once && !untriggered) this.destroy()
+  } finally {
+    this._wasTop = atTop
+    this._wasBottom = atBottom
+    this._wasLeft = atLeft
+    this._wasRight = atRight
+    this._wasFit = fits
+  }
 }
diff --git a/src/viewport.js b/src/viewport.js
index ae4be41..e37e261 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -16,10 +16,14 @@ export function Viewport(container, observerCollection) {
       requestAnimationFrame(() => {
         const { observers } = this
         const state = this.getState()
-        for (let i = observers.length; i--; ) observers[i].check(state)
-        this.lastX = state.positionX
-        this.lastY = state.positionY
-        scheduled = false
+
+        try {
+          for (let i = observers.length; i--; ) observers[i].check(state)
+        } finally {
+          this.lastX = state.positionX
+          this.lastY = state.positionY
+          scheduled = false
+        }
       })
     }
   }
diff --git a/test/index.js b/test/index.js
index fb13d96..ccf7264 100644
--- a/test/index.js
+++ b/test/index.js
@@ -196,7 +196,60 @@ describe('viewprt', () => {
       await testObserverType('ElementObserver')
     })
 
-    it('destroys after trigging with once option', async () => {
+    it('recovers from observer exceptions', async () => {
+      assert.ok(
+        await page.evaluate(pageHeight => {
+          const content = document.createElement('div')
+          const contentHeight = pageHeight * 2
+          content.style.height = contentHeight + 'px'
+          document.body.appendChild(content)
+
+          return new Promise(resolve => {
+            PositionObserver({
+              onTop() {
+                setTimeout(() => resolve(true))
+              },
+              onBottom() {
+                throw new Error()
+              }
+            })
+            window.scrollTo(0, contentHeight)
+            setTimeout(() => window.scrollTo(0, 0), 65)
+          })
+        }, pageHeight)
+      )
+
+      await closePage()
+      await createPage()
+
+      assert.ok(
+        await page.evaluate(pageHeight => {
+          const content = document.createElement('div')
+          const contentHeight = pageHeight * 2
+          content.style.height = contentHeight + 'px'
+          document.body.appendChild(content)
+
+          const element = document.createElement('div')
+          element.style.height = '10px'
+          document.body.appendChild(element)
+
+          return new Promise(resolve => {
+            ElementObserver(element, {
+              onEnter() {
+                throw new Error()
+              },
+              onExit() {
+                setTimeout(() => resolve(true))
+              }
+            })
+            window.scrollTo(0, contentHeight)
+            setTimeout(() => window.scrollTo(0, 0), 65)
+          })
+        }, pageHeight)
+      )
+    })
+
+    it('destroys after triggering with once option', async () => {
       assert.ok(
         await page.evaluate(pageHeight => {
           const content = document.createElement('div')