diff --git a/include/cling/Interpreter/Transaction.h b/include/cling/Interpreter/Transaction.h
index 9d936076..be3c807c 100644
--- a/include/cling/Interpreter/Transaction.h
+++ b/include/cling/Interpreter/Transaction.h
@@ -268,22 +268,7 @@ namespace cling {
     ///
     ///\param[in] nested - The transaction to be nested.
     ///
-    void addNestedTransaction(Transaction* nested) {
-      // Create lazily the list
-      if (!m_NestedTransactions)
-        m_NestedTransactions.reset(new NestedTransactions());
-
-      // Lazy create the container on first append.
-      if (!m_DeclQueue)
-        m_DeclQueue.reset(new DeclQueue());
-
-      nested->setParent(this);
-      // Leave a marker in the parent transaction, where the nested transaction
-      // started.
-      DelayCallInfo marker(clang::DeclGroupRef(), Transaction::kCCINone);
-      m_DeclQueue->push_back(marker);
-      m_NestedTransactions->push_back(nested);
-    }
+    void addNestedTransaction(Transaction* nested);
 
     ///\brief Removes a nested transaction.
     ///
diff --git a/lib/Interpreter/Transaction.cpp b/lib/Interpreter/Transaction.cpp
index 95d67fe1..1d459102 100644
--- a/lib/Interpreter/Transaction.cpp
+++ b/lib/Interpreter/Transaction.cpp
@@ -26,6 +26,24 @@ namespace cling {
       }
   }
 
+  void Transaction::addNestedTransaction(Transaction* nested) {
+    // Create lazily the list
+    if (!m_NestedTransactions)
+      m_NestedTransactions.reset(new NestedTransactions());
+
+    // Lazy create the container on first append.
+    if (!m_DeclQueue)
+      m_DeclQueue.reset(new DeclQueue());
+
+    nested->setParent(this);
+    // Leave a marker in the parent transaction, where the nested transaction
+    // started.
+    DelayCallInfo marker(clang::DeclGroupRef(), Transaction::kCCINone);
+    m_DeclQueue->push_back(marker);
+    m_NestedTransactions->push_back(nested);
+  }
+
+
   void Transaction::removeNestedTransaction(Transaction* nested) {
     assert(hasNestedTransactions() && "Does not contain nested transactions");
     int nestedPos = -1;