diff --git a/fos/fos-selection/fos-selection.component.ts b/fos/fos-selection/fos-selection.component.ts
index e978ea88..64d50cfa 100644
--- a/fos/fos-selection/fos-selection.component.ts
+++ b/fos/fos-selection/fos-selection.component.ts
@@ -72,8 +72,9 @@ export class FosSelectionComponent {
           } else {
             this.activeSection = this.fos[0].id;
           }
-
-          this.setObserver();
+          if(typeof IntersectionObserver !== "undefined") {
+            this.setObserver();
+          }
           this.cdr.detectChanges();
         });
       }
@@ -93,7 +94,7 @@ export class FosSelectionComponent {
       this.subscriptions.push(this.keywordControl.valueChanges.pipe(debounceTime(500), distinctUntilChanged()).subscribe(value => {
         this.keyword = value;
         this.findMatches(this.keyword);
-        if (typeof document !== 'undefined') {
+        if (typeof IntersectionObserver !== 'undefined') {
           setTimeout(() => {
             this.setObserver();
           });
diff --git a/fos/fos.component.ts b/fos/fos.component.ts
index 90664f4b..49edfd5b 100644
--- a/fos/fos.component.ts
+++ b/fos/fos.component.ts
@@ -105,7 +105,7 @@ export class FosComponent implements OnInit, OnDestroy {
 			this.subscriptions.push(this.keywordControl.valueChanges.pipe(debounceTime(500), distinctUntilChanged()).subscribe(value => {
 				this.keyword = value;
 				this.findMatches(this.keyword);
-				if (typeof document !== 'undefined') {
+				if (typeof IntersectionObserver !== 'undefined') {
 					setTimeout(() => {
 						this.setObserver();
 					});