diff --git a/src/key_io.cpp b/src/key_io.cpp
index 29002afc457..6cece47e410 100644
--- a/src/key_io.cpp
+++ b/src/key_io.cpp
@@ -274,6 +274,9 @@ CExtKey DecodeExtKey(const std::string& str)
             key.Decode(data.data() + prefix.size());
         }
     }
+    if (!data.empty()) {
+        memory_cleanse(data.data(), data.size());
+    }
     return key;
 }