diff --git a/.gitignore b/.gitignore
index 8f313ddbc..6d624695a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -388,3 +388,4 @@ support/time remaining test.xlsx
 test/vs2022/Debug MSVC C++20 - Force C++03
 test/vs2022/Release MSVC C++20 - No STL - Optimised -O2 - Sanitiser
 test/test_file_list.txt
+test/etl_error_handler/assert_function/build-make
diff --git a/include/etl/singleton_base.h b/include/etl/singleton_base.h
index 6b68aafb0..eb9653b4b 100644
--- a/include/etl/singleton_base.h
+++ b/include/etl/singleton_base.h
@@ -39,6 +39,7 @@ SOFTWARE.
 
 #include "platform.h"
 #include "error_handler.h"
+#include "nullptr.h"
 #include "file_error_numbers.h"
 
 namespace etl
@@ -93,7 +94,7 @@ namespace etl
   /// Usage example:
   ///
   /// class Origin
-  /// :   singleton<Origin>
+  ///   : singleton<Origin>
   /// {
   /// public:
   ///     Origin(int x, int y)
@@ -112,43 +113,52 @@ namespace etl
   /// to be created by the user before calling instance(). This way, the user has better control
   /// over the instance lifetime instead of e.g. lazy initialization.
   //***********************************************************************
-  template<class T>
+  template <typename T>
   class singleton_base
   {
-  protected:
+  public:
 
     //***********************************************************************
-    /// Constructs the instance of singleton.
-    /// theInstance Reference to T, which will be returned when instance() is called.
+    // Returns a reference to the instance.
     //***********************************************************************
-    explicit singleton_base(T& theInstance)
+    static T& instance()
     {
-      ETL_ASSERT(m_self == nullptr, ETL_ERROR(etl::singleton_base_already_created));
-      m_self = &theInstance;
+      ETL_ASSERT(m_self != ETL_NULLPTR, ETL_ERROR(etl::singleton_base_not_created));
+
+      return *m_self;
     }
 
     //***********************************************************************
-    /// Removes the internal reference to the instance passed in the constructor.
+    /// Returns whether an instance has been attached to singleton<T> or not.
     //***********************************************************************
-    ~singleton_base() { m_self = nullptr; }
+    static bool is_valid() 
+    { 
+      return (m_self != ETL_NULLPTR); 
+    }
 
-  public:
+  protected:
 
     //***********************************************************************
-    // Returns a reference to the instance.
+    /// Constructs the instance of singleton.
+    /// theInstance Reference to T, which will be returned when instance() is called.
     //***********************************************************************
-    static T& instance()
+    explicit singleton_base(T& theInstance)
     {
-      ETL_ASSERT(m_self != nullptr, ETL_ERROR(etl::singleton_base_not_created));
-      return *m_self;
+      ETL_ASSERT(m_self == ETL_NULLPTR, ETL_ERROR(etl::singleton_base_already_created));
+
+      m_self = &theInstance;
     }
 
     //***********************************************************************
-    /// Returns whether an instance has been attached to singleton<T> or not.
+    /// Removes the internal reference to the instance passed in the constructor.
     //***********************************************************************
-    static bool is_valid() { return (m_self != nullptr); }
+    ~singleton_base() 
+    { 
+      m_self = ETL_NULLPTR; 
+    }
 
   private:
+
     static T* m_self;
   };
 
@@ -156,7 +166,7 @@ namespace etl
   /// No violation of one definition rule as this is a class template
   //***********************************************************************
   template<class T>
-  T* singleton_base<T>::m_self = nullptr;
+  T* singleton_base<T>::m_self = ETL_NULLPTR;
 }
 
 #endif
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index ce9e2a664..90b9fbb4c 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -233,6 +233,7 @@ add_executable(etl_tests
 	test_set.cpp
 	test_shared_message.cpp
 	test_singleton.cpp
+	test_singleton_base.cpp
 	test_smallest.cpp
 	test_span_dynamic_extent.cpp
 	test_span_fixed_extent.cpp
diff --git a/test/syntax_check/c++03/CMakeLists.txt b/test/syntax_check/c++03/CMakeLists.txt
index fad0c6eb0..651b23e60 100644
--- a/test/syntax_check/c++03/CMakeLists.txt
+++ b/test/syntax_check/c++03/CMakeLists.txt
@@ -260,6 +260,7 @@ target_sources(t98 PRIVATE etl_profile.h
 		../set.h.t.cpp
 		../shared_message.h.t.cpp
 		../singleton.h.t.cpp
+		../singleton_base.h.t.cpp
 		../smallest.h.t.cpp
 		../span.h.t.cpp
 		../sqrt.h.t.cpp
diff --git a/test/syntax_check/c++11/CMakeLists.txt b/test/syntax_check/c++11/CMakeLists.txt
index f426cecca..68c48d232 100644
--- a/test/syntax_check/c++11/CMakeLists.txt
+++ b/test/syntax_check/c++11/CMakeLists.txt
@@ -260,6 +260,7 @@ target_sources(t11 PRIVATE etl_profile.h
 		../set.h.t.cpp
 		../shared_message.h.t.cpp
 		../singleton.h.t.cpp
+		../singleton_base.h.t.cpp
 		../smallest.h.t.cpp
 		../span.h.t.cpp
 		../sqrt.h.t.cpp
diff --git a/test/syntax_check/c++14/CMakeLists.txt b/test/syntax_check/c++14/CMakeLists.txt
index b7bc68b99..5d50945fd 100644
--- a/test/syntax_check/c++14/CMakeLists.txt
+++ b/test/syntax_check/c++14/CMakeLists.txt
@@ -260,6 +260,7 @@ target_sources(t14 PRIVATE etl_profile.h
 		../set.h.t.cpp
 		../shared_message.h.t.cpp
 		../singleton.h.t.cpp
+		../singleton_base.h.t.cpp
 		../smallest.h.t.cpp
 		../span.h.t.cpp
 		../sqrt.h.t.cpp
diff --git a/test/syntax_check/c++17/CMakeLists.txt b/test/syntax_check/c++17/CMakeLists.txt
index 5d8761ab2..be7879086 100644
--- a/test/syntax_check/c++17/CMakeLists.txt
+++ b/test/syntax_check/c++17/CMakeLists.txt
@@ -260,6 +260,7 @@ target_sources(t17 PRIVATE etl_profile.h
 		../set.h.t.cpp
 		../shared_message.h.t.cpp
 		../singleton.h.t.cpp
+		../singleton_base.h.t.cpp
 		../smallest.h.t.cpp
 		../span.h.t.cpp
 		../sqrt.h.t.cpp
diff --git a/test/syntax_check/c++20/CMakeLists.txt b/test/syntax_check/c++20/CMakeLists.txt
index f38c48ada..71a5bb167 100644
--- a/test/syntax_check/c++20/CMakeLists.txt
+++ b/test/syntax_check/c++20/CMakeLists.txt
@@ -260,6 +260,7 @@ target_sources(t20 PRIVATE etl_profile.h
 		../set.h.t.cpp
 		../shared_message.h.t.cpp
 		../singleton.h.t.cpp
+		../singleton_base.h.t.cpp
 		../smallest.h.t.cpp
 		../span.h.t.cpp
 		../sqrt.h.t.cpp
diff --git a/test/syntax_check/singleton_base.h.t.cpp b/test/syntax_check/singleton_base.h.t.cpp
new file mode 100644
index 000000000..723ffcf9e
--- /dev/null
+++ b/test/syntax_check/singleton_base.h.t.cpp
@@ -0,0 +1,29 @@
+/******************************************************************************
+The MIT License(MIT)
+
+Embedded Template Library.
+https://github.com/ETLCPP/etl
+https://www.etlcpp.com
+
+Copyright(c) 2024 John Wellbelove
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files(the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+#include <etl/singleton_base.h>
diff --git a/test/test_singleton_base.cpp b/test/test_singleton_base.cpp
index 40cfa5430..fec07c59a 100644
--- a/test/test_singleton_base.cpp
+++ b/test/test_singleton_base.cpp
@@ -34,7 +34,7 @@ SOFTWARE.
 #include <string>
 #include <type_traits>
 
-class Test_Singleton: public ::etl::singleton_base<Test_Singleton>
+class Test_Singleton: public etl::singleton_base<Test_Singleton>
 {
 public:
 
@@ -62,7 +62,6 @@ namespace
     //*************************************************************************
     TEST(test1)
     {
-
       CHECK(!Test_Singleton::is_valid());
       CHECK_THROW(Test_Singleton::instance(), etl::singleton_base_not_created);
 
diff --git a/test/vs2022/etl.vcxproj b/test/vs2022/etl.vcxproj
index 7506cfa14..7809c4383 100644
--- a/test/vs2022/etl.vcxproj
+++ b/test/vs2022/etl.vcxproj
@@ -3190,6 +3190,7 @@
     <ClInclude Include="..\..\include\etl\scaled_rounding.h" />
     <ClInclude Include="..\..\include\etl\shared_message.h" />
     <ClInclude Include="..\..\include\etl\singleton.h" />
+    <ClInclude Include="..\..\include\etl\singleton_base.h" />
     <ClInclude Include="..\..\include\etl\span.h" />
     <ClInclude Include="..\..\include\etl\standard_deviation.h" />
     <ClInclude Include="..\..\include\etl\state_chart.h" />
@@ -7076,6 +7077,21 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++14 - No STL|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - Force C++03|Win32'">true</ExcludedFromBuild>
     </ClCompile>
+    <ClCompile Include="..\syntax_check\singleton_base.h.t.cpp">
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - No virtual imessage|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++ 20 - No Tests|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - No STL|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++14|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release MSVC C++20 - No STL - Optimised -O2|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release MSVC C++20 - No STL - Optimised -O2 - Sanitiser|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++17|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++17 - No STL|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release MSVC C++20 - Optimised O2|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - No virtual messages|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++14 - No STL|Win32'">true</ExcludedFromBuild>
+      <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - Force C++03|Win32'">true</ExcludedFromBuild>
+    </ClCompile>
     <ClCompile Include="..\syntax_check\smallest.h.t.cpp">
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20|Win32'">true</ExcludedFromBuild>
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Debug MSVC C++20 - No virtual imessage|Win32'">true</ExcludedFromBuild>
@@ -8912,6 +8928,7 @@
       <ExcludedFromBuild Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</ExcludedFromBuild>
     </ClCompile>
     <ClCompile Include="..\test_singleton.cpp" />
+    <ClCompile Include="..\test_singleton_base.cpp" />
     <ClCompile Include="..\test_span_dynamic_extent.cpp" />
     <ClCompile Include="..\test_span_fixed_extent.cpp" />
     <ClCompile Include="..\test_standard_deviation.cpp" />