diff --git a/src/ol/structs/rbush.js b/src/ol/structs/rbush.js
index 549c3be3da..e0bdc81819 100644
--- a/src/ol/structs/rbush.js
+++ b/src/ol/structs/rbush.js
@@ -574,6 +574,14 @@ ol.structs.RBush.prototype.insert_ = function(extent, value, level) {
 };
 
 
+/**
+ * @return {boolean} Is empty.
+ */
+ol.structs.RBush.prototype.isEmpty = function() {
+  return this.root_.children.length === 0;
+};
+
+
 /**
  * @param {T} value Value.
  */
diff --git a/test/spec/ol/structs/rbush.test.js b/test/spec/ol/structs/rbush.test.js
index cdf6b7167d..250aa374b5 100644
--- a/test/spec/ol/structs/rbush.test.js
+++ b/test/spec/ol/structs/rbush.test.js
@@ -18,6 +18,14 @@ describe('ol.structs.RBush', function() {
 
     });
 
+    describe('#isEmpty', function() {
+
+      it('returns true', function() {
+        expect(rBush.isEmpty()).to.be(true);
+      });
+
+    });
+
   });
 
   describe('with a few objects', function() {
@@ -76,6 +84,14 @@ describe('ol.structs.RBush', function() {
           });
     });
 
+    describe('#isEmpty', function() {
+
+      it('returns false', function() {
+        expect(rBush.isEmpty()).to.be(false);
+      });
+
+    });
+
     describe('#remove', function() {
 
       it('can remove each object', function() {
@@ -155,6 +171,14 @@ describe('ol.structs.RBush', function() {
 
     });
 
+    describe('#isEmpty', function() {
+
+      it('returns false', function() {
+        expect(rBush.isEmpty()).to.be(false);
+      });
+
+    });
+
     describe('#remove', function() {
 
       it('can remove each object in turn', function() {
@@ -165,6 +189,7 @@ describe('ol.structs.RBush', function() {
           expect(rBush.getAllInExtent(extents[i])).to.be.empty();
         }
         expect(rBush.getAll()).to.be.empty();
+        expect(rBush.isEmpty()).to.be(true);
       });
 
       it('can remove objects in random order', function() {
@@ -183,6 +208,7 @@ describe('ol.structs.RBush', function() {
           expect(rBush.getAllInExtent(extents[index])).to.be.empty();
         }
         expect(rBush.getAll()).to.be.empty();
+        expect(rBush.isEmpty()).to.be(true);
       });
 
     });
@@ -260,6 +286,14 @@ describe('ol.structs.RBush', function() {
 
     });
 
+    describe('#isEmpty', function() {
+
+      it('returns false', function() {
+        expect(rBush.isEmpty()).to.be(false);
+      });
+
+    });
+
   });
 
 });