1 files changed, 1 insertions, 0 deletions
diff --git a/src/script/script.h b/src/script/script.h
index 587f2d26eb..2a92060543 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -420,6 +420,7 @@ public:
 
     CScript& operator+=(const CScript& b)
     {
+        reserve(size() + b.size());
         insert(end(), b.begin(), b.end());
         return *this;
     }