diff --git a/word/macroeditor.go b/word/macroeditor.go
index 577bce6..74444b4 100644
--- a/word/macroeditor.go
+++ b/word/macroeditor.go
@@ -78,7 +78,19 @@ func modifyEntry(f *zip2.File, injectionTarget MacroInjectTarget) *[]byte {
 	if err != nil {
 		panic(err)
 	}
+
+	buff := bytes.Buffer{}
+
 	idx := bytes.Index(content, injectionTarget.Marker)
-	copy(content[idx:idx+len(injectionTarget.Marker)], injectionTarget.Replacement[0:])
-	return &content
+	if idx < 0 { //we didn't find the tag
+		return &content
+	}
+	buff.Write(content[0:idx])
+	buff.Write(injectionTarget.Replacement)
+	buff.Write(content[(idx + len(injectionTarget.Marker)):])
+
+	//copy(content[idx:idx+len(injectionTarget.Marker)], injectionTarget.Replacement[0:])
+
+	ret := buff.Bytes()
+	return &ret
 }