diff --git a/filei_test.go b/filei_test.go
index ae0a630..be43fbc 100644
--- a/filei_test.go
+++ b/filei_test.go
@@ -130,8 +130,8 @@ func TestFiles(t *testing.T) {
 		t.Fatalf("Files() error = %v", err)
 	}
 
-	if len(data) != 7 {
-		t.Fatal("Files() error data must have 7 files")
+	if len(data) != 8 {
+		t.Fatal("Files() error data must have 8 files")
 	}
 }
 
@@ -161,3 +161,17 @@ func TestChmod(t *testing.T) {
 		t.Errorf("Chmod() error data must have a value")
 	}
 }
+
+func TestPrepend(t *testing.T) {
+	filePath := "testdata/pre-app.txt"
+
+	err := Prepend(filePath, "The first line\n")
+	if err != nil {
+		t.Errorf("Prepend() error = %v", err)
+	}
+
+	err = Prepend("wrong path", "The first line\n")
+	if err == nil {
+		t.Errorf("Prepend() error data must have a value")
+	}
+}
diff --git a/testdata/pre-app.txt b/testdata/pre-app.txt
new file mode 100644
index 0000000..1ddd7f2
--- /dev/null
+++ b/testdata/pre-app.txt
@@ -0,0 +1,3 @@
+The first line
+The first line
+The first line