diff --git a/boost/iostreams/device/mapped_file.hpp b/boost/iostreams/device/mapped_file.hpp
index 1332beabd..6d705d601 100644
--- a/boost/iostreams/device/mapped_file.hpp
+++ b/boost/iostreams/device/mapped_file.hpp
@@ -142,6 +142,10 @@ struct basic_mapped_file_params
         : base_type(other), path(other.path)
         { }
 
+    // Copy assignment operator
+    basic_mapped_file_params& operator=(
+        const basic_mapped_file_params& other) = default;
+
     typedef Path  path_type;
     Path          path;
 };
@@ -186,6 +190,9 @@ class BOOST_IOSTREAMS_DECL mapped_file_source : public mapped_file_base {
     // Copy Constructor
     mapped_file_source(const mapped_file_source& other);
 
+    // Copy assignment operator
+    mapped_file_source& operator=(const mapped_file_source& other) = default;
+
     //--------------Stream interface------------------------------------------//
 
     template<typename Path>
@@ -269,6 +276,9 @@ class BOOST_IOSTREAMS_DECL mapped_file : public mapped_file_base {
     // Copy Constructor
     mapped_file(const mapped_file& other);
 
+    // Copy assignment operator
+    mapped_file& operator=(const mapped_file& other) = default;
+
     //--------------Conversion to mapped_file_source (deprecated)-------------//
 
     operator mapped_file_source&() { return delegate_; }
@@ -372,6 +382,9 @@ class BOOST_IOSTREAMS_DECL mapped_file_sink : private mapped_file {
     // Copy Constructor
     mapped_file_sink(const mapped_file_sink& other);
 
+    // Copy assignment operator
+    mapped_file_sink& operator=(const mapped_file_sink& other) = default;
+
     // open overload taking a parameters object
     template<typename Path>
     void open(const basic_mapped_file_params<Path>& p);