diff --git a/src/Mod/Assembly/App/BomObject.cpp b/src/Mod/Assembly/App/BomObject.cpp
index 83761e0f5c..54fcb4b14f 100644
--- a/src/Mod/Assembly/App/BomObject.cpp
+++ b/src/Mod/Assembly/App/BomObject.cpp
@@ -24,7 +24,6 @@
 #include <cmath>
 #include <vector>
 
-
 #include <App/Application.h>
 #include <App/Document.h>
 #include <App/DocumentObjectGroup.h>
@@ -43,7 +42,6 @@
 #include <Mod/PartDesign/App/Body.h>
 #include <Mod/Spreadsheet/App/Cell.h>
 
-
 #include "AssemblyObject.h"
 #include "AssemblyLink.h"
 #include "BomObject.h"
@@ -291,19 +289,19 @@ std::string BomObject::getBomPropertyValue(App::DocumentObject* obj, const std::
     if (auto propStr = freecad_cast<App::PropertyString*>(prop)) {
         return propStr->getValue();
     }
-    else if (auto propQuantity = freecad_cast<App::PropertyQuantity*>(prop)) {
+    if (auto propQuantity = freecad_cast<App::PropertyQuantity*>(prop)) {
         return propQuantity->getQuantityValue().getUserString();
     }
-    else if (auto propEnum = freecad_cast<App::PropertyEnumeration*>(prop)) {
+    if (auto propEnum = freecad_cast<App::PropertyEnumeration*>(prop)) {
         return propEnum->getValueAsString();
     }
-    else if (auto propFloat = freecad_cast<App::PropertyFloat*>(prop)) {
+    if (auto propFloat = freecad_cast<App::PropertyFloat*>(prop)) {
         return std::to_string(propFloat->getValue());
     }
-    else if (auto propInt = freecad_cast<App::PropertyInteger*>(prop)) {
+    if (auto propInt = freecad_cast<App::PropertyInteger*>(prop)) {
         return std::to_string(propInt->getValue());
     }
-    else if (auto propBool = freecad_cast<App::PropertyBool*>(prop)) {
+    if (auto propBool = freecad_cast<App::PropertyBool*>(prop)) {
         return propBool->getValue() ? "True" : "False";
     }
 
@@ -311,7 +309,7 @@ std::string BomObject::getBomPropertyValue(App::DocumentObject* obj, const std::
     return QObject::tr("Not supported").toStdString();
 }
 
-AssemblyObject* BomObject::getAssembly()
+AssemblyObject* BomObject::getAssembly() const
 {
     for (auto& obj : getInList()) {
         if (obj->isDerivedFrom<AssemblyObject>()) {
@@ -321,7 +319,7 @@ AssemblyObject* BomObject::getAssembly()
     return nullptr;
 }
 
-bool BomObject::hasQuantityColumn()
+bool BomObject::hasQuantityColumn() const
 {
     for (auto& columnName : columnsNames.getValues()) {
         if (columnName == "Quantity") {
@@ -331,9 +329,9 @@ bool BomObject::hasQuantityColumn()
     return false;
 }
 
-std::string Assembly::BomObject::getText(size_t row, size_t col)
+std::string Assembly::BomObject::getText(size_t row, size_t col) const
 {
-    Spreadsheet::Cell* cell = getCell(App::CellAddress(row, col));
+    const Spreadsheet::Cell* cell = getCell(App::CellAddress(row, col));
     std::string cellName;
     if (cell) {
         cell->getStringContent(cellName);
@@ -347,7 +345,7 @@ std::string Assembly::BomObject::getText(size_t row, size_t col)
     return cellName;
 }
 
-int BomObject::getColumnIndex(std::string name)
+int BomObject::getColumnIndex(std::string name) const
 {
     int col = 0;
     for (auto& columnName : columnsNames.getValues()) {
diff --git a/src/Mod/Assembly/App/BomObject.h b/src/Mod/Assembly/App/BomObject.h
index c1e4954323..2ea18d81b7 100644
--- a/src/Mod/Assembly/App/BomObject.h
+++ b/src/Mod/Assembly/App/BomObject.h
@@ -80,11 +80,11 @@ public:
     void addObjectChildrenToBom(std::vector<App::DocumentObject*> objs, size_t& row, std::string index);
     void saveCustomColumnData();
 
-    AssemblyObject* getAssembly();
+    AssemblyObject* getAssembly() const;
 
-    bool hasQuantityColumn();
-    int getColumnIndex(std::string name);
-    std::string getText(size_t row, size_t col);
+    bool hasQuantityColumn() const;
+    int getColumnIndex(std::string name) const;
+    std::string getText(size_t row, size_t col) const;
 
     App::PropertyStringList columnsNames;
     App::PropertyBool detailSubAssemblies;
diff --git a/src/Mod/Spreadsheet/App/Sheet.cpp b/src/Mod/Spreadsheet/App/Sheet.cpp
index e0fb337f07..df27045ea7 100644
--- a/src/Mod/Spreadsheet/App/Sheet.cpp
+++ b/src/Mod/Spreadsheet/App/Sheet.cpp
@@ -411,6 +411,17 @@ Cell* Sheet::getCell(CellAddress address)
     return cells.getValue(address);
 }
 
+/**
+ * Get contents of the cell specified by \a address, or 0 if it is not defined
+ *
+ * @returns A CellContent object or 0.
+ */
+
+const Cell* Sheet::getCell(CellAddress address) const
+{
+    return cells.getValue(address);
+}
+
 /**
  * Get cell contents specified by \a address.
  *
diff --git a/src/Mod/Spreadsheet/App/Sheet.h b/src/Mod/Spreadsheet/App/Sheet.h
index 6b347db8e7..74ff2c11cc 100644
--- a/src/Mod/Spreadsheet/App/Sheet.h
+++ b/src/Mod/Spreadsheet/App/Sheet.h
@@ -110,6 +110,7 @@ public:
     void splitCell(App::CellAddress address);
 
     Cell* getCell(App::CellAddress address);
+    const Cell* getCell(App::CellAddress address) const;
 
     Cell* getNewCell(App::CellAddress address);