diff --git a/src/io/io.go b/src/io/io.go
index 7b8ee10a56..bcb9f774f6 100644
--- a/src/io/io.go
+++ b/src/io/io.go
@@ -575,6 +575,10 @@ func (o *OffsetWriter) Write(p []byte) (n int, err error) {
 }
 
 func (o *OffsetWriter) WriteAt(p []byte, off int64) (n int, err error) {
+	if off < 0 {
+		return 0, errOffset
+	}
+
 	off += o.base
 	return o.w.WriteAt(p, off)
 }
diff --git a/src/io/io_test.go b/src/io/io_test.go
index 35db15c3ba..c09b5e34d2 100644
--- a/src/io/io_test.go
+++ b/src/io/io_test.go
@@ -608,6 +608,26 @@ func TestOffsetWriter_WriteAt(t *testing.T) {
 	}
 }
 
+func TestWriteAt_PositionPriorToBase(t *testing.T) {
+	tmpdir := t.TempDir()
+	tmpfilename := "TestOffsetWriter_WriteAt"
+	tmpfile, err := os.CreateTemp(tmpdir, tmpfilename)
+	if err != nil {
+		t.Fatalf("CreateTemp(%s) failed: %v", tmpfilename, err)
+	}
+	defer tmpfile.Close()
+
+	// start writing position in OffsetWriter
+	offset := int64(10)
+	// position we want to write to the tmpfile
+	at := int64(-1)
+	w := NewOffsetWriter(tmpfile, offset)
+	_, e := w.WriteAt([]byte("hello"), at)
+	if e == nil {
+		t.Errorf("error expected to be not nil")
+	}
+}
+
 func TestOffsetWriter_Write(t *testing.T) {
 	const content = "0123456789ABCDEF"
 	contentSize := len(content)