diff --git a/elfio/elfio.hpp b/elfio/elfio.hpp
index bdbbd4f..32e4b2b 100644
--- a/elfio/elfio.hpp
+++ b/elfio/elfio.hpp
@@ -281,7 +281,7 @@ class elfio
             return 0;
         }
 
-        new_section->set_index( sections_.size() );
+        new_section->set_index( (Elf_Half)sections_.size() );
         sections_.push_back( new_section );
 
         return new_section;
diff --git a/elfio/elfio_note.hpp b/elfio/elfio_note.hpp
index cf93710..b839eaf 100644
--- a/elfio/elfio_note.hpp
+++ b/elfio/elfio_note.hpp
@@ -40,7 +40,7 @@ class note_section_accessor
     Elf_Word
     get_notes_num() const
     {
-        return note_start_positions.size();
+        return (Elf_Word)note_start_positions.size();
     }
 
 //------------------------------------------------------------------------------
@@ -85,7 +85,7 @@ class note_section_accessor
     {
         const endianess_convertor& convertor = elf_file.get_convertor();
 
-        Elf_Word nameLen     = name.size() + 1;
+        Elf_Word nameLen     = (Elf_Word)name.size() + 1;
         Elf_Word nameLenConv = convertor( nameLen );
         std::string buffer( reinterpret_cast<char*>( &nameLenConv ), sizeof( nameLenConv ) );
         Elf_Word descSizeConv = convertor( descSize );
diff --git a/elfio/elfio_section.hpp b/elfio/elfio_section.hpp
index 9b46b86..bf4890a 100644
--- a/elfio/elfio_section.hpp
+++ b/elfio/elfio_section.hpp
@@ -162,7 +162,7 @@ class section_impl : public section
     void
     set_data( const std::string& str_data )
     {
-        return set_data( str_data.c_str(), str_data.size() );
+        return set_data( str_data.c_str(), (Elf_Word)str_data.size() );
     }
 
 //------------------------------------------------------------------------------
@@ -191,7 +191,7 @@ class section_impl : public section
     void
     append_data( const std::string& str_data )
     {
-        return append_data( str_data.c_str(), str_data.size() );
+        return append_data( str_data.c_str(), (Elf_Word)str_data.size() );
     }
 
 //------------------------------------------------------------------------------
diff --git a/elfio/elfio_segment.hpp b/elfio/elfio_segment.hpp
index d61df84..be90d8b 100644
--- a/elfio/elfio_segment.hpp
+++ b/elfio/elfio_segment.hpp
@@ -112,14 +112,14 @@ class segment_impl : public segment
             set_align( addr_align );
         }
 
-        return sections.size();
+        return (Elf_Half)sections.size();
     }
 
 //------------------------------------------------------------------------------
     Elf_Half
     get_sections_num() const
     {
-        return sections.size();
+        return (Elf_Half)sections.size();
     }
 
 //------------------------------------------------------------------------------
diff --git a/elfio/elfio_strings.hpp b/elfio/elfio_strings.hpp
index fa37b83..4c688cf 100644
--- a/elfio/elfio_strings.hpp
+++ b/elfio/elfio_strings.hpp
@@ -67,7 +67,7 @@ class string_section_accessor
             string_section->append_data( empty_string, 1 );
             current_position++;
         }
-        string_section->append_data( str, std::strlen( str ) + 1 );
+        string_section->append_data( str, (Elf_Word)std::strlen( str ) + 1 );
 
         return current_position;
     }