diff --git a/ortools/constraint_solver/CMakeLists.txt b/ortools/constraint_solver/CMakeLists.txt
index 3cb19a91b9..a578370fa6 100644
--- a/ortools/constraint_solver/CMakeLists.txt
+++ b/ortools/constraint_solver/CMakeLists.txt
@@ -20,6 +20,10 @@ add_library(${NAME} OBJECT ${_SRCS})
 set_target_properties(${NAME} PROPERTIES
   POSITION_INDEPENDENT_CODE ON
   )
+if(MSVC AND BUILD_SHARED_LIBS)
+  target_compile_definitions(${NAME} PUBLIC "OR_BUILD_DLL")
+  target_compile_definitions(${NAME} PRIVATE "OR_EXPORT")
+endif()
 target_include_directories(${NAME} PRIVATE
   ${PROJECT_SOURCE_DIR}
   ${PROJECT_BINARY_DIR})
diff --git a/ortools/constraint_solver/constraint_solveri.h b/ortools/constraint_solver/constraint_solveri.h
index 2b31b49ac9..39f6dae213 100644
--- a/ortools/constraint_solver/constraint_solveri.h
+++ b/ortools/constraint_solver/constraint_solveri.h
@@ -2291,7 +2291,7 @@ class LocalSearchFilterManager : public BaseObject {
   int64_t accepted_value_;
 };
 
-class IntVarLocalSearchFilter : public LocalSearchFilter {
+class OR_DLL IntVarLocalSearchFilter : public LocalSearchFilter {
  public:
   explicit IntVarLocalSearchFilter(const std::vector<IntVar*>& vars);
   ~IntVarLocalSearchFilter() override;
diff --git a/ortools/constraint_solver/routing.h b/ortools/constraint_solver/routing.h
index 10e00fcc36..6ee0ce6690 100644
--- a/ortools/constraint_solver/routing.h
+++ b/ortools/constraint_solver/routing.h
@@ -251,7 +251,7 @@ class PathsMetadata {
   std::vector<int64_t> path_of_node_;
 };
 
-class RoutingModel {
+class OR_DLL RoutingModel {
  public:
   /// Types of precedence policy applied to pickup and delivery pairs.
   enum PickupAndDeliveryPolicy {
@@ -2837,7 +2837,7 @@ class RoutingModel {
 };
 
 /// Routing model visitor.
-class RoutingModelVisitor : public BaseObject {
+class OR_DLL RoutingModelVisitor : public BaseObject {
  public:
   /// Constraint types.
   static const char kLightElement[];
diff --git a/ortools/init/CMakeLists.txt b/ortools/init/CMakeLists.txt
index ff9d22ea23..f5fbec03c0 100644
--- a/ortools/init/CMakeLists.txt
+++ b/ortools/init/CMakeLists.txt
@@ -21,6 +21,10 @@ set_target_properties(${NAME} PROPERTIES
   LINKER_LANGUAGE CXX
   POSITION_INDEPENDENT_CODE ON
   )
+if(MSVC AND BUILD_SHARED_LIBS)
+  target_compile_definitions(${NAME} PUBLIC "OR_BUILD_DLL")
+  target_compile_definitions(${NAME} PRIVATE "OR_EXPORT")
+endif()
 target_include_directories(${NAME} PRIVATE
   ${PROJECT_SOURCE_DIR}
   ${PROJECT_BINARY_DIR})
diff --git a/ortools/linear_solver/CMakeLists.txt b/ortools/linear_solver/CMakeLists.txt
index aadecdab2b..9902bd9239 100644
--- a/ortools/linear_solver/CMakeLists.txt
+++ b/ortools/linear_solver/CMakeLists.txt
@@ -29,6 +29,10 @@ add_library(${NAME} OBJECT ${_SRCS})
 set_target_properties(${NAME} PROPERTIES
   POSITION_INDEPENDENT_CODE ON
   )
+if(MSVC AND BUILD_SHARED_LIBS)
+  target_compile_definitions(${NAME} PUBLIC "OR_BUILD_DLL")
+  target_compile_definitions(${NAME} PRIVATE "OR_EXPORT")
+endif()
 target_include_directories(${NAME} PUBLIC
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}>
   $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}>)
diff --git a/ortools/linear_solver/linear_solver.h b/ortools/linear_solver/linear_solver.h
index 4dee0ee7c3..1ea5aeb54f 100644
--- a/ortools/linear_solver/linear_solver.h
+++ b/ortools/linear_solver/linear_solver.h
@@ -1469,7 +1469,7 @@ class MPConstraint {
  * instead. We need to figure out how to deal with the subtleties of
  * the default values.
  */
-class MPSolverParameters {
+class OR_DLL MPSolverParameters {
  public:
   /// Enumeration of parameters that take continuous values.
   enum DoubleParam {