diff --git a/dbms/src/DataStreams/RollupBlockInputStream.cpp b/dbms/src/DataStreams/RollupBlockInputStream.cpp
index 389dbf5bec5..00766b1a390 100644
--- a/dbms/src/DataStreams/RollupBlockInputStream.cpp
+++ b/dbms/src/DataStreams/RollupBlockInputStream.cpp
@@ -1,4 +1,5 @@
 #include <DataStreams/RollupBlockInputStream.h>
+#include <DataStreams/finalizeBlock.h>
 #include <DataTypes/DataTypeAggregateFunction.h>
 #include <Columns/ColumnAggregateFunction.h>
 #include <Columns/FilterDescription.h>
@@ -6,23 +7,7 @@
 
 namespace DB
 {
-
-static void finalize(Block & block)
-{
-    for (size_t i = 0; i < block.columns(); ++i)
-    {
-        ColumnWithTypeAndName & current = block.getByPosition(i);
-        const DataTypeAggregateFunction * unfinalized_type = typeid_cast<const DataTypeAggregateFunction *>(current.type.get());
-
-        if (unfinalized_type)
-        {
-            current.type = unfinalized_type->getReturnType();
-            if (current.column)
-                current.column = typeid_cast<const ColumnAggregateFunction &>(*current.column).convertToValues();
-        }
-    }
-}
-
+    
 RollupBlockInputStream::RollupBlockInputStream(
     const BlockInputStreamPtr & input_, const Aggregator::Params & params_) : aggregator(params_),
         keys(params_.keys)
@@ -36,7 +21,7 @@ RollupBlockInputStream::RollupBlockInputStream(
 Block RollupBlockInputStream::getHeader() const
 {
     Block res = children.at(0)->getHeader();
-    finalize(res);
+    finalizeBlock(res);
     return res;
 }
 
@@ -58,7 +43,7 @@ Block RollupBlockInputStream::readImpl()
         rollup_block = aggregator.mergeBlocks(rollup_blocks, false);
 
         Block finalized = rollup_block;
-        finalize(finalized);
+        finalizeBlock(finalized);
         return finalized;
     }
 
@@ -66,7 +51,7 @@ Block RollupBlockInputStream::readImpl()
     current_key = keys.size() - 1;
 
     rollup_block = block;
-    finalize(block);
+    finalizeBlock(block);
 
     return block;
 }
diff --git a/dbms/src/DataStreams/TotalsHavingBlockInputStream.cpp b/dbms/src/DataStreams/TotalsHavingBlockInputStream.cpp
index e964065822c..103d880f1d3 100644
--- a/dbms/src/DataStreams/TotalsHavingBlockInputStream.cpp
+++ b/dbms/src/DataStreams/TotalsHavingBlockInputStream.cpp
@@ -1,4 +1,5 @@
 #include <DataStreams/TotalsHavingBlockInputStream.h>
+#include <DataStreams/finalizeBlock.h>
 #include <Interpreters/ExpressionActions.h>
 #include <DataTypes/DataTypeAggregateFunction.h>
 #include <Columns/ColumnAggregateFunction.h>
@@ -53,23 +54,6 @@ TotalsHavingBlockInputStream::TotalsHavingBlockInputStream(
 }
 
 
-static void finalize(Block & block)
-{
-    for (size_t i = 0; i < block.columns(); ++i)
-    {
-        ColumnWithTypeAndName & current = block.getByPosition(i);
-        const DataTypeAggregateFunction * unfinalized_type = typeid_cast<const DataTypeAggregateFunction *>(current.type.get());
-
-        if (unfinalized_type)
-        {
-            current.type = unfinalized_type->getReturnType();
-            if (current.column)
-                current.column = typeid_cast<const ColumnAggregateFunction &>(*current.column).convertToValues();
-        }
-    }
-}
-
-
 Block TotalsHavingBlockInputStream::getTotals()
 {
     if (!totals)
@@ -87,7 +71,7 @@ Block TotalsHavingBlockInputStream::getTotals()
         }
 
         totals = children.at(0)->getHeader().cloneWithColumns(std::move(current_totals));
-        finalize(totals);
+        finalizeBlock(totals);
     }
 
     if (totals && expression)
@@ -101,7 +85,7 @@ Block TotalsHavingBlockInputStream::getHeader() const
 {
     Block res = children.at(0)->getHeader();
     if (final)
-        finalize(res);
+        finalizeBlock(res);
     if (expression)
         expression->execute(res);
     return res;
@@ -129,7 +113,7 @@ Block TotalsHavingBlockInputStream::readImpl()
 
         finalized = block;
         if (final)
-            finalize(finalized);
+            finalizeBlock(finalized);
 
         total_keys += finalized.rows();
 
diff --git a/dbms/src/DataStreams/finalizeBlock.cpp b/dbms/src/DataStreams/finalizeBlock.cpp
new file mode 100644
index 00000000000..11b9a297227
--- /dev/null
+++ b/dbms/src/DataStreams/finalizeBlock.cpp
@@ -0,0 +1,24 @@
+#include <DataStreams/finalizeBlock.h>
+#include <DataTypes/DataTypeAggregateFunction.h>
+#include <Columns/ColumnAggregateFunction.h>
+#include <Common/typeid_cast.h>
+
+
+namespace DB
+{
+    void finalizeBlock(Block & block)
+    {
+        for (size_t i = 0; i < block.columns(); ++i)
+        {
+            ColumnWithTypeAndName & current = block.getByPosition(i);
+            const DataTypeAggregateFunction * unfinalized_type = typeid_cast<const DataTypeAggregateFunction *>(current.type.get());
+
+            if (unfinalized_type)
+            {
+                current.type = unfinalized_type->getReturnType();
+                if (current.column)
+                    current.column = typeid_cast<const ColumnAggregateFunction &>(*current.column).convertToValues();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/dbms/src/DataStreams/finalizeBlock.h b/dbms/src/DataStreams/finalizeBlock.h
new file mode 100644
index 00000000000..db0ef6968b2
--- /dev/null
+++ b/dbms/src/DataStreams/finalizeBlock.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <Core/Block.h>
+
+namespace DB
+{
+    /// Converts aggregate function columns with non-finalized states to final values
+    void finalizeBlock(Block & block);
+}
\ No newline at end of file