diff --git a/tsdb/head_test.go b/tsdb/head_test.go
index 2aa97cd44..3d271e93b 100644
--- a/tsdb/head_test.go
+++ b/tsdb/head_test.go
@@ -5499,3 +5499,49 @@ func TestCuttingNewHeadChunks(t *testing.T) {
 		})
 	}
 }
+
+// TestHeadDetectsDuplcateSampleAtSizeLimit tests a regression where a duplicate sample
+// is appended to the head, right when the head chunk is at the size limit.
+// The test adds all samples as duplicate, thus expecting that the result has
+// exactly half of the samples.
+func TestHeadDetectsDuplicateSampleAtSizeLimit(t *testing.T) {
+	numSamples := 1000
+	baseTS := int64(1695209650)
+
+	h, _ := newTestHead(t, DefaultBlockDuration, wlog.CompressionNone, false)
+	defer func() {
+		require.NoError(t, h.Close())
+	}()
+
+	a := h.Appender(context.Background())
+	var err error
+	vals := []float64{math.MaxFloat64, 0x00} // Use the worst case scenario for the XOR encoding. Otherwise we hit the sample limit before the size limit.
+	for i := 0; i < numSamples; i++ {
+		ts := baseTS + int64(i/2)*10000
+		a.Append(0, labels.FromStrings("foo", "bar"), ts, vals[(i/2)%len(vals)])
+		err = a.Commit()
+		require.NoError(t, err)
+		a = h.Appender(context.Background())
+	}
+
+	indexReader, err := h.Index()
+	require.NoError(t, err)
+
+	var (
+		chunks  []chunks.Meta
+		builder labels.ScratchBuilder
+	)
+	require.NoError(t, indexReader.Series(1, &builder, &chunks))
+
+	chunkReader, err := h.Chunks()
+	require.NoError(t, err)
+
+	storedSampleCount := 0
+	for _, chunkMeta := range chunks {
+		chunk, err := chunkReader.Chunk(chunkMeta)
+		require.NoError(t, err)
+		storedSampleCount += chunk.NumSamples()
+	}
+
+	require.Equal(t, numSamples/2, storedSampleCount)
+}