diff --git a/src/functions/functions.spec.ts b/src/functions/functions.spec.ts
index fc64ada..decd771 100644
--- a/src/functions/functions.spec.ts
+++ b/src/functions/functions.spec.ts
@@ -1405,6 +1405,7 @@ test.cb("parallel() parallel mapping", t => {
 });
 
 test.cb.only("accumulator() buffering strategy", t => {
+    let chunkIndex = 0;
     interface TestObject {
         ts: number;
         key: string;
@@ -1417,6 +1418,7 @@ test.cb.only("accumulator() buffering strategy", t => {
         { ts: 2, key: "d" },
         { ts: 3, key: "e" },
     ];
+
     source
         .pipe(
             accumulator(FlushStrategy.sampling, {
@@ -1424,17 +1426,17 @@ test.cb.only("accumulator() buffering strategy", t => {
             }),
         )
         .on("data", (flush: TestObject[]) => {
-            console.log("FLUSH", flush);
-            flush.forEach(item => expectedElements.includes(item));
-        })
-        .on("error", e => {
-            console.log("Got error: ", e);
-            t.end();
+            if (chunkIndex === 0) {
+                chunkIndex++;
+                t.deepEqual(flush, expectedElements.slice(0, 4));
+            } else {
+                t.deepEqual(flush, expectedElements.slice(4));
+            }
         })
+        .on("error", e => t.end)
         .on("end", () => {
-            console.log("end");
             t.end();
         });
-    source.push(expectedElements);
+    expectedElements.forEach(element => source.push(element));
     source.push(null);
 });
diff --git a/src/functions/functions.ts b/src/functions/functions.ts
index 2cc2d78..40a534c 100644
--- a/src/functions/functions.ts
+++ b/src/functions/functions.ts
@@ -644,10 +644,11 @@ export function accumulator<T, R, S extends FlushStrategy>(
     const buffer: Array<T> = [];
     return new Transform({
         objectMode: true,
-        async transform(data, encoding, callback) {
+        async transform(data: T[] | T, encoding, callback) {
             callback();
             switch (flushStrategy) {
                 case FlushStrategy.sampling: {
+                    if (!Array.isArray(data)) data = [data];
                     executeSamplingStrategy(
                         data,
                         options as SamplingFlushOptions<T, R>,