diff --git a/elfio/elfio_dynamic.hpp b/elfio/elfio_dynamic.hpp
index a0c483c..3464a03 100644
--- a/elfio/elfio_dynamic.hpp
+++ b/elfio/elfio_dynamic.hpp
@@ -23,6 +23,8 @@ THE SOFTWARE.
 #ifndef ELFIO_DYNAMIC_HPP
 #define ELFIO_DYNAMIC_HPP
 
+#include <algorithm>
+
 namespace ELFIO {
 
 //------------------------------------------------------------------------------
@@ -31,21 +33,30 @@ template <class S> class dynamic_section_accessor_template
   public:
     //------------------------------------------------------------------------------
     dynamic_section_accessor_template( const elfio& elf_file_, S* section_ )
-        : elf_file( elf_file_ ), dynamic_section( section_ )
+        : elf_file( elf_file_ ), dynamic_section( section_ ), entries_num( 0 )
     {
     }
 
     //------------------------------------------------------------------------------
     Elf_Xword get_entries_num() const
     {
-        Elf_Xword nRet = 0;
-
-        if ( 0 != dynamic_section->get_entry_size() ) {
-            nRet =
+        if ( ( 0 == entries_num ) &&
+             ( 0 != dynamic_section->get_entry_size() ) ) {
+            entries_num =
                 dynamic_section->get_size() / dynamic_section->get_entry_size();
+            Elf_Xword   i;
+            Elf_Xword   tag;
+            Elf_Xword   value;
+            std::string str;
+            for ( i = 0; i < entries_num; i++ ) {
+                get_entry( i, tag, value, str );
+                if ( tag == DT_NULL )
+                    break;
+            }
+            entries_num = std::min( entries_num, i + 1 );
         }
 
-        return nRet;
+        return entries_num;
     }
 
     //------------------------------------------------------------------------------
@@ -234,8 +245,9 @@ template <class S> class dynamic_section_accessor_template
 
     //------------------------------------------------------------------------------
   private:
-    const elfio& elf_file;
-    S*           dynamic_section;
+    const elfio&      elf_file;
+    S*                dynamic_section;
+    mutable Elf_Xword entries_num;
 };
 
 using dynamic_section_accessor = dynamic_section_accessor_template<section>;
diff --git a/elfio/elfio_modinfo.hpp b/elfio/elfio_modinfo.hpp
index a169cf1..9bf5429 100644
--- a/elfio/elfio_modinfo.hpp
+++ b/elfio/elfio_modinfo.hpp
@@ -56,7 +56,7 @@ template <class S> class modinfo_section_accessor_template
     }
 
     //------------------------------------------------------------------------------
-    bool get_attribute( std::string field_name, std::string& value ) const
+    bool get_attribute( const std::string field_name, std::string& value ) const
     {
         for ( auto i = content.begin(); i != content.end(); i++ ) {
             if ( field_name == i->first ) {
@@ -69,7 +69,7 @@ template <class S> class modinfo_section_accessor_template
     }
 
     //------------------------------------------------------------------------------
-    Elf_Word add_attribute( std::string field, std::string value )
+    Elf_Word add_attribute( const std::string field, const std::string value )
     {
         Elf_Word current_position = 0;
 
diff --git a/tests/ELFIOTest.cpp b/tests/ELFIOTest.cpp
index f37b9db..867f24b 100644
--- a/tests/ELFIOTest.cpp
+++ b/tests/ELFIOTest.cpp
@@ -892,7 +892,7 @@ BOOST_AUTO_TEST_CASE( test_dynamic_64_1 )
 
     dynamic_section_accessor da( reader, dynsec );
 
-    BOOST_CHECK_EQUAL( da.get_entries_num(), 26 );
+    BOOST_CHECK_EQUAL( da.get_entries_num(), 21 );
 
     Elf_Xword   tag;
     Elf_Xword   value;
@@ -926,7 +926,7 @@ BOOST_AUTO_TEST_CASE( test_dynamic_64_2 )
 
     dynamic_section_accessor da( reader, dynsec );
 
-    BOOST_CHECK_EQUAL( da.get_entries_num(), 24 );
+    BOOST_CHECK_EQUAL( da.get_entries_num(), 20 );
 
     Elf_Xword   tag;
     Elf_Xword   value;
@@ -956,7 +956,7 @@ BOOST_AUTO_TEST_CASE( test_dynamic_64_3 )
     BOOST_REQUIRE( dynsec != NULL );
 
     dynamic_section_accessor da( reader, dynsec );
-    BOOST_CHECK_EQUAL( da.get_entries_num(), 26 );
+    BOOST_CHECK_EQUAL( da.get_entries_num(), 21 );
 
     section* strsec1 = reader.sections.add( ".dynstr" );
     strsec1->set_type( SHT_STRTAB );