diff --git a/src/lib/deskflow/IClipboard.cpp b/src/lib/deskflow/IClipboard.cpp
index 2c23f8663..d4394f7d4 100644
--- a/src/lib/deskflow/IClipboard.cpp
+++ b/src/lib/deskflow/IClipboard.cpp
@@ -27,13 +27,13 @@ void IClipboard::unmarshall(IClipboard *clipboard, const std::string_view &data,
     // clear existing data
     clipboard->empty();
 
-    // read the number of formats
-    const uint32_t numFormats = readUInt32(index);
     if (end - index < 4) {
       LOG_ERR("clipboard unmarshall: truncated header");
       clipboard->close();
       return;
     }
+    // read the number of formats
+    const uint32_t numFormats = readUInt32(index);
     index += 4;
 
     // read each format