diff --git a/code/Exceptional.h b/code/Exceptional.h
index e04da757c..3268423ef 100644
--- a/code/Exceptional.h
+++ b/code/Exceptional.h
@@ -58,8 +58,8 @@ class DeadlyImportError
 {
 public:
     /** Constructor with arguments */
-    explicit DeadlyImportError( const std::string& pErrorText)
-        : runtime_error(pErrorText)
+    explicit DeadlyImportError( const std::string& errorText)
+        : runtime_error(errorText)
     {
     }
 
diff --git a/include/assimp/Exporter.hpp b/include/assimp/Exporter.hpp
index 079060f4b..18f5fb744 100644
--- a/include/assimp/Exporter.hpp
+++ b/include/assimp/Exporter.hpp
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  Exporter.hpp
 *  @brief Defines the CPP-API for the Assimp export interface
 */
+#pragma once
 #ifndef AI_EXPORT_HPP_INC
 #define AI_EXPORT_HPP_INC
 
diff --git a/include/assimp/IOStream.hpp b/include/assimp/IOStream.hpp
index 6cc231b3d..b0bc5ebb6 100644
--- a/include/assimp/IOStream.hpp
+++ b/include/assimp/IOStream.hpp
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief File I/O wrappers for C++.
  */
 
+#pragma once
 #ifndef AI_IOSTREAM_H_INC
 #define AI_IOSTREAM_H_INC
 
diff --git a/include/assimp/IOSystem.hpp b/include/assimp/IOSystem.hpp
index abd7e5837..9a5876edf 100644
--- a/include/assimp/IOSystem.hpp
+++ b/include/assimp/IOSystem.hpp
@@ -44,6 +44,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  custom file handling logic to the Import library.
 */
 
+#pragma once
 #ifndef AI_IOSYSTEM_H_INC
 #define AI_IOSYSTEM_H_INC
 
diff --git a/include/assimp/Importer.hpp b/include/assimp/Importer.hpp
index 4c01367ed..f7b8c00f3 100644
--- a/include/assimp/Importer.hpp
+++ b/include/assimp/Importer.hpp
@@ -42,12 +42,13 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  Importer.hpp
  *  @brief Defines the C++-API to the Open Asset Import Library.
  */
-#ifndef INCLUDED_AI_ASSIMP_HPP
-#define INCLUDED_AI_ASSIMP_HPP
+#pragma once
+#ifndef AI_ASSIMP_HPP_INC
+#define AI_ASSIMP_HPP_INC
 
 #ifndef __cplusplus
 #   error This header requires C++ to be used. Use assimp.h for plain C.
-#endif
+#endif // __cplusplus
 
 // Public ASSIMP data structures
 #include "types.h"
@@ -658,4 +659,5 @@ AI_FORCE_INLINE bool Importer::IsExtensionSupported(const std::string& szExtensi
 }
 
 } // !namespace Assimp
-#endif // INCLUDED_AI_ASSIMP_HPP
+
+#endif // AI_ASSIMP_HPP_INC
diff --git a/include/assimp/ProgressHandler.hpp b/include/assimp/ProgressHandler.hpp
index 8b069c82e..1ac016efb 100644
--- a/include/assimp/ProgressHandler.hpp
+++ b/include/assimp/ProgressHandler.hpp
@@ -41,9 +41,12 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file ProgressHandler.hpp
  *  @brief Abstract base class 'ProgressHandler'.
  */
-#ifndef INCLUDED_AI_PROGRESSHANDLER_H
-#define INCLUDED_AI_PROGRESSHANDLER_H
+#pragma once
+#ifndef AI_PROGRESSHANDLER_H_INC
+#define AI_PROGRESSHANDLER_H_INC
+
 #include "types.h"
+
 namespace Assimp    {
 
 // ------------------------------------------------------------------------------------
@@ -119,4 +122,4 @@ public:
 // ------------------------------------------------------------------------------------
 } // Namespace Assimp
 
-#endif
+#endif // AI_PROGRESSHANDLER_H_INC
diff --git a/include/assimp/ai_assert.h b/include/assimp/ai_assert.h
index 0caeff673..fa63c329c 100644
--- a/include/assimp/ai_assert.h
+++ b/include/assimp/ai_assert.h
@@ -38,15 +38,15 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ---------------------------------------------------------------------------
 */
-#ifndef AI_DEBUG_H_INC
-#define AI_DEBUG_H_INC
+#pragma once
+#ifndef AI_ASSERT_H_INC
+#define AI_ASSERT_H_INC
 
 #ifdef ASSIMP_BUILD_DEBUG
 #   include <assert.h>
 #   define  ai_assert(expression) assert(expression)
 #else
 #   define  ai_assert(expression)
-#endif
+#endif // 
 
-
-#endif
+#endif // AI_ASSERT_H_INC
diff --git a/include/assimp/anim.h b/include/assimp/anim.h
index af5941755..ea70cc170 100644
--- a/include/assimp/anim.h
+++ b/include/assimp/anim.h
@@ -43,6 +43,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Defines the data structures in which the imported animations
  *  are returned.
  */
+#pragma once
 #ifndef AI_ANIM_H_INC
 #define AI_ANIM_H_INC
 
diff --git a/include/assimp/camera.h b/include/assimp/camera.h
index 37f1bdaa0..6b9fbbea5 100644
--- a/include/assimp/camera.h
+++ b/include/assimp/camera.h
@@ -43,6 +43,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Defines the aiCamera data structure
  */
 
+#pragma once
 #ifndef AI_CAMERA_H_INC
 #define AI_CAMERA_H_INC
 
diff --git a/include/assimp/cexport.h b/include/assimp/cexport.h
index 71cb1f8ec..17a491b8e 100644
--- a/include/assimp/cexport.h
+++ b/include/assimp/cexport.h
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  cexport.h
 *  @brief Defines the C-API for the Assimp export interface
 */
+#pragma once
 #ifndef AI_EXPORT_H_INC
 #define AI_EXPORT_H_INC
 
diff --git a/include/assimp/cfileio.h b/include/assimp/cfileio.h
index d91974b78..f9f121207 100644
--- a/include/assimp/cfileio.h
+++ b/include/assimp/cfileio.h
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file cfileio.h
  *  @brief Defines generic C routines to access memory-mapped files
  */
+#pragma once
 #ifndef AI_FILEIO_H_INC
 #define AI_FILEIO_H_INC
 
diff --git a/include/assimp/cimport.h b/include/assimp/cimport.h
index de0cbae30..ad06e669a 100644
--- a/include/assimp/cimport.h
+++ b/include/assimp/cimport.h
@@ -42,8 +42,10 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  cimport.h
  *  @brief Defines the C-API to the Open Asset Import Library.
  */
+#pragma once
 #ifndef AI_ASSIMP_H_INC
 #define AI_ASSIMP_H_INC
+
 #include "types.h"
 #include "importerdesc.h"
 
diff --git a/include/assimp/color4.h b/include/assimp/color4.h
index 6bcab45df..8371cdeeb 100644
--- a/include/assimp/color4.h
+++ b/include/assimp/color4.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file color4.h
  *  @brief RGBA color structure, including operators when compiling in C++
  */
+#pragma once
 #ifndef AI_COLOR4D_H_INC
 #define AI_COLOR4D_H_INC
 
diff --git a/include/assimp/color4.inl b/include/assimp/color4.inl
index d69814714..219372ef2 100644
--- a/include/assimp/color4.inl
+++ b/include/assimp/color4.inl
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  color4.inl
  *  @brief Inline implementation of aiColor4t<TReal> operators
  */
+#pragma once
 #ifndef AI_COLOR4D_INL_INC
 #define AI_COLOR4D_INL_INC
 
diff --git a/include/assimp/config.h b/include/assimp/config.h
index 3db8a5697..842646b4d 100644
--- a/include/assimp/config.h
+++ b/include/assimp/config.h
@@ -55,8 +55,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  #aiSetImportPropertyFloat,
  *  #aiSetImportPropertyString
  */
-#ifndef INCLUDED_AI_CONFIG_H
-#define INCLUDED_AI_CONFIG_H
+#pragma once
+#ifndef AI_CONFIG_H_INC
+#define AI_CONFIG_H_INC
 
 
 // ###########################################################################
diff --git a/include/assimp/defs.h b/include/assimp/defs.h
index 2c9749357..5cc431787 100644
--- a/include/assimp/defs.h
+++ b/include/assimp/defs.h
@@ -44,8 +44,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  blocks to find out how to customize _your_ Assimp build.
  */
 
-#ifndef INCLUDED_AI_DEFINES_H
-#define INCLUDED_AI_DEFINES_H
+#pragma once
+#ifndef AI_DEFINES_H_INC
+#define AI_DEFINES_H_INC
 
     //////////////////////////////////////////////////////////////////////////
     /* Define ASSIMP_BUILD_NO_XX_IMPORTER to disable a specific
@@ -269,4 +270,4 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define AI_MAX_ALLOC(type) ((256U * 1024 * 1024) / sizeof(type))
 
 
-#endif // !! INCLUDED_AI_DEFINES_H
+#endif // !! AI_DEFINES_H_INC
diff --git a/include/assimp/importerdesc.h b/include/assimp/importerdesc.h
index b2b123aca..455f83cce 100644
--- a/include/assimp/importerdesc.h
+++ b/include/assimp/importerdesc.h
@@ -42,8 +42,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file importerdesc.h
  *  @brief #aiImporterFlags, aiImporterDesc implementation.
  */
-#ifndef INCLUDED_AI_IMPORTER_DESC_H
-#define INCLUDED_AI_IMPORTER_DESC_H
+#pragma once
+#ifndef AI_IMPORTER_DESC_H_INC
+#define AI_IMPORTER_DESC_H_INC
 
 
 /** Mixed set of flags for #aiImporterDesc, indicating some features
@@ -140,4 +141,4 @@ Will return a NULL-pointer if no assigned importer desc. was found for the given
 */
 ASSIMP_API const C_STRUCT aiImporterDesc* aiGetImporterDesc( const char *extension );
 
-#endif
+#endif // AI_IMPORTER_DESC_H_INC
diff --git a/include/assimp/light.h b/include/assimp/light.h
index 939d5b6cd..9a7893b52 100644
--- a/include/assimp/light.h
+++ b/include/assimp/light.h
@@ -43,8 +43,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Defines the aiLight data structure
  */
 
-#ifndef __AI_LIGHT_H_INC__
-#define __AI_LIGHT_H_INC__
+#pragma once
+#ifndef AI_LIGHT_H_INC
+#define AI_LIGHT_H_INC
 
 #include "types.h"
 
@@ -250,7 +251,7 @@ struct aiLight
 
 #ifdef __cplusplus
 }
-#endif
+#endif 
 
 
-#endif // !! __AI_LIGHT_H_INC__
+#endif // !! AI_LIGHT_H_INC
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 87d27c569..def0e819b 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -42,7 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file material.h
  *  @brief Defines the material system of the library
  */
-
+#pragma once
 #ifndef AI_MATERIAL_H_INC
 #define AI_MATERIAL_H_INC
 
diff --git a/include/assimp/material.inl b/include/assimp/material.inl
index 994e608b4..ef9c62f0d 100644
--- a/include/assimp/material.inl
+++ b/include/assimp/material.inl
@@ -43,6 +43,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Defines the C++ getters for the material system
  */
 
+#pragma once
 #ifndef AI_MATERIAL_INL_INC
 #define AI_MATERIAL_INL_INC
 
diff --git a/include/assimp/matrix3x3.h b/include/assimp/matrix3x3.h
index 725b1c34c..544d20b49 100644
--- a/include/assimp/matrix3x3.h
+++ b/include/assimp/matrix3x3.h
@@ -42,8 +42,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file matrix3x3.h
  *  @brief Definition of a 3x3 matrix, including operators when compiling in C++
  */
-#ifndef AI_MATRIX3x3_H_INC
-#define AI_MATRIX3x3_H_INC
+#pragma once
+#ifndef AI_MATRIX3X3_H_INC
+#define AI_MATRIX3X3_H_INC
 
 #include "./Compiler/pushpack1.h"
 
@@ -179,4 +180,4 @@ struct aiMatrix3x3 {
 
 #include "./Compiler/poppack1.h"
 
-#endif // AI_MATRIX3x3_H_INC
+#endif // AI_MATRIX3X3_H_INC
diff --git a/include/assimp/matrix3x3.inl b/include/assimp/matrix3x3.inl
index 9ace3f97b..2ef0141e8 100644
--- a/include/assimp/matrix3x3.inl
+++ b/include/assimp/matrix3x3.inl
@@ -42,8 +42,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file matrix3x3.inl
  *  @brief Inline implementation of the 3x3 matrix operators
  */
-#ifndef AI_MATRIX3x3_INL_INC
-#define AI_MATRIX3x3_INL_INC
+#pragma once
+#ifndef AI_MATRIX3X3_INL_INC
+#define AI_MATRIX3X3_INL_INC
 
 #ifdef __cplusplus
 #include "matrix3x3.h"
@@ -333,4 +334,4 @@ inline aiMatrix3x3t<TReal>& aiMatrix3x3t<TReal>::FromToMatrix(const aiVector3t<T
 
 
 #endif // __cplusplus
-#endif // AI_MATRIX3x3_INL_INC
+#endif // AI_MATRIX3X3_INL_INC
diff --git a/include/assimp/matrix4x4.h b/include/assimp/matrix4x4.h
index fc77b6964..368e77cc6 100644
--- a/include/assimp/matrix4x4.h
+++ b/include/assimp/matrix4x4.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file matrix4x4.h
  *  @brief 4x4 matrix structure, including operators when compiling in C++
  */
+#pragma once
 #ifndef AI_MATRIX4X4_H_INC
 #define AI_MATRIX4X4_H_INC
 
diff --git a/include/assimp/matrix4x4.inl b/include/assimp/matrix4x4.inl
index 9ce794f0a..2ccd557d8 100644
--- a/include/assimp/matrix4x4.inl
+++ b/include/assimp/matrix4x4.inl
@@ -42,8 +42,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file matrix4x4.inl
  *  @brief Inline implementation of the 4x4 matrix operators
  */
-#ifndef AI_MATRIX4x4_INL_INC
-#define AI_MATRIX4x4_INL_INC
+#pragma once
+#ifndef AI_MATRIX4X4_INL_INC
+#define AI_MATRIX4X4_INL_INC
 
 #ifdef __cplusplus
 
@@ -538,4 +539,4 @@ inline aiMatrix4x4t<TReal>& aiMatrix4x4t<TReal>::FromToMatrix(const aiVector3t<T
 }
 
 #endif // __cplusplus
-#endif // AI_MATRIX4x4_INL_INC
+#endif // AI_MATRIX4X4_INL_INC
diff --git a/include/assimp/mesh.h b/include/assimp/mesh.h
index a76a2d72b..fd7560b83 100644
--- a/include/assimp/mesh.h
+++ b/include/assimp/mesh.h
@@ -43,8 +43,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Declares the data structures in which the imported geometry is
     returned by ASSIMP: aiMesh, aiFace and aiBone data structures.
  */
-#ifndef INCLUDED_AI_MESH_H
-#define INCLUDED_AI_MESH_H
+#pragma once
+#ifndef AI_MESH_H_INC
+#define AI_MESH_H_INC
 
 #include "types.h"
 
@@ -736,5 +737,5 @@ struct aiMesh
 #ifdef __cplusplus
 }
 #endif //! extern "C"
-#endif // __AI_MESH_H_INC
+#endif // AI_MESH_H_INC
 
diff --git a/include/assimp/metadata.h b/include/assimp/metadata.h
index 814d89272..5ed8f9f9b 100644
--- a/include/assimp/metadata.h
+++ b/include/assimp/metadata.h
@@ -42,8 +42,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file metadata.h
  *  @brief Defines the data structures for holding node meta information.
  */
-#ifndef __AI_METADATA_H_INC__
-#define __AI_METADATA_H_INC__
+#pragma once
+#ifndef AI_METADATA_H_INC
+#define AI_METADATA_H_INC
 
 #include <assert.h>
 
@@ -246,6 +247,6 @@ struct aiMetadata
 
 };
 
-#endif // __AI_METADATA_H_INC__
+#endif // AI_METADATA_H_INC
 
 
diff --git a/include/assimp/postprocess.h b/include/assimp/postprocess.h
index 04de7a275..53c22da13 100644
--- a/include/assimp/postprocess.h
+++ b/include/assimp/postprocess.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file postprocess.h
  *  @brief Definitions for import post processing steps
  */
+#pragma once
 #ifndef AI_POSTPROCESS_H_INC
 #define AI_POSTPROCESS_H_INC
 
diff --git a/include/assimp/quaternion.h b/include/assimp/quaternion.h
index fe213f71e..edf442d62 100644
--- a/include/assimp/quaternion.h
+++ b/include/assimp/quaternion.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file quaternion.h
  *  @brief Quaternion structure, including operators when compiling in C++
  */
+#pragma once
 #ifndef AI_QUATERNION_H_INC
 #define AI_QUATERNION_H_INC
 
@@ -122,5 +123,4 @@ struct aiQuaternion {
 
 #endif
 
-
 #endif // AI_QUATERNION_H_INC
diff --git a/include/assimp/quaternion.inl b/include/assimp/quaternion.inl
index db27c25ff..68cb5a236 100644
--- a/include/assimp/quaternion.inl
+++ b/include/assimp/quaternion.inl
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  quaternion.inl
  *  @brief Inline implementation of aiQuaterniont<TReal> operators
  */
+#pragma once
 #ifndef AI_QUATERNION_INL_INC
 #define AI_QUATERNION_INL_INC
 
@@ -280,4 +281,4 @@ inline aiVector3t<TReal> aiQuaterniont<TReal>::Rotate (const aiVector3t<TReal>&
 }
 
 #endif
-#endif
+#endif // AI_QUATERNION_INL_INC
diff --git a/include/assimp/scene.h b/include/assimp/scene.h
index 8987ac6a3..b3c56c7f1 100644
--- a/include/assimp/scene.h
+++ b/include/assimp/scene.h
@@ -38,12 +38,14 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ---------------------------------------------------------------------------
 */
+#pragma once
 
 /** @file scene.h
  *  @brief Defines the data structures in which the imported scene is returned.
  */
-#ifndef __AI_SCENE_H_INC__
-#define __AI_SCENE_H_INC__
+#pragma once
+#ifndef AI_SCENE_H_INC
+#define AI_SCENE_H_INC
 
 #include "types.h"
 #include "texture.h"
@@ -425,4 +427,4 @@ struct aiScene
 } //! namespace Assimp
 #endif
 
-#endif // __AI_SCENE_H_INC__
+#endif // AI_SCENE_H_INC
diff --git a/include/assimp/texture.h b/include/assimp/texture.h
index ee3ee3149..b0fe695d4 100644
--- a/include/assimp/texture.h
+++ b/include/assimp/texture.h
@@ -47,7 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  * pixels, and "compressed" textures, which are stored in a file format
  * such as PNG or TGA.
  */
-
+#pragma once
 #ifndef AI_TEXTURE_H_INC
 #define AI_TEXTURE_H_INC
 
diff --git a/include/assimp/types.h b/include/assimp/types.h
index 592d5c64d..cdffce841 100644
--- a/include/assimp/types.h
+++ b/include/assimp/types.h
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file types.h
  *  Basic data types and primitives, such as vectors or colors.
  */
+#pragma once
 #ifndef AI_TYPES_H_INC
 #define AI_TYPES_H_INC
 
@@ -512,4 +513,5 @@ struct aiMemoryInfo
 #include "quaternion.inl"
 #include "matrix3x3.inl"
 #include "matrix4x4.inl"
-#endif
+
+#endif // AI_TYPES_H_INC
diff --git a/include/assimp/vector2.h b/include/assimp/vector2.h
index 199743e26..a664cbecb 100644
--- a/include/assimp/vector2.h
+++ b/include/assimp/vector2.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file vector2.h
  *  @brief 2D vector structure, including operators when compiling in C++
  */
+#pragma once
 #ifndef AI_VECTOR2D_H_INC
 #define AI_VECTOR2D_H_INC
 
diff --git a/include/assimp/vector2.inl b/include/assimp/vector2.inl
index ae823fc1a..ce6521139 100644
--- a/include/assimp/vector2.inl
+++ b/include/assimp/vector2.inl
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  vector2.inl
  *  @brief Inline implementation of aiVector2t<TReal> operators
  */
+#pragma once
 #ifndef AI_VECTOR2D_INL_INC
 #define AI_VECTOR2D_INL_INC
 
@@ -221,4 +222,5 @@ inline aiVector2t<TReal> operator - ( const aiVector2t<TReal>& v)
 }
 
 #endif
-#endif
+
+#endif // AI_VECTOR2D_INL_INC
diff --git a/include/assimp/vector3.h b/include/assimp/vector3.h
index 84f785f8f..45571f84b 100644
--- a/include/assimp/vector3.h
+++ b/include/assimp/vector3.h
@@ -41,6 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file vector3.h
  *  @brief 3D vector structure, including operators when compiling in C++
  */
+#pragma once
 #ifndef AI_VECTOR3D_H_INC
 #define AI_VECTOR3D_H_INC
 
diff --git a/include/assimp/vector3.inl b/include/assimp/vector3.inl
index 0d0d62968..22b5bca03 100644
--- a/include/assimp/vector3.inl
+++ b/include/assimp/vector3.inl
@@ -42,6 +42,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 /** @file  vector3.inl
  *  @brief Inline implementation of aiVector3t<TReal> operators
  */
+#pragma once
 #ifndef AI_VECTOR3D_INL_INC
 #define AI_VECTOR3D_INL_INC
 
diff --git a/include/assimp/version.h b/include/assimp/version.h
index 403798c1b..a9b2beb5b 100644
--- a/include/assimp/version.h
+++ b/include/assimp/version.h
@@ -43,8 +43,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *  @brief Functions to query the version of the Assimp runtime, check
  *    compile flags, ...
  */
-#ifndef INCLUDED_AI_VERSION_H
-#define INCLUDED_AI_VERSION_H
+#pragma once
+#ifndef AI_VERSION_H_INC
+#define AI_VERSION_H_INC
 
 #include "defs.h"
 
@@ -102,4 +103,4 @@ ASSIMP_API unsigned int aiGetCompileFlags (void);
 } // end extern "C"
 #endif
 
-#endif // !! #ifndef INCLUDED_AI_VERSION_H
+#endif // !! #ifndef AI_VERSION_H_INC
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index df0139ddc..97af3f90a 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -85,6 +85,7 @@ SET( TEST_SRCS
   unit/utTextureTransform.cpp
   unit/utTriangulate.cpp
   unit/utVertexTriangleAdjacency.cpp
+  unit/utVersion.cpp
 )
 
 SOURCE_GROUP( tests FILES  ${TEST_SRCS} )
diff --git a/test/unit/utVersion.cpp b/test/unit/utVersion.cpp
new file mode 100644
index 000000000..d8953f866
--- /dev/null
+++ b/test/unit/utVersion.cpp
@@ -0,0 +1,69 @@
+/*-------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2016, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+-------------------------------------------------------------------------*/
+#include "UnitTestPCH.h"
+#include <assimp/version.h>
+
+class utVersion : public ::testing::Test {
+    // empty
+};
+
+TEST_F( utVersion, aiGetLegalStringTest ) {
+    const char *lv( aiGetLegalString() );
+    EXPECT_NE( lv, nullptr );
+    std::string text( lv );
+
+    size_t pos( text.find( std::string( "2016" ) ) );
+    EXPECT_NE( pos, std::string::npos );
+}
+
+TEST_F( utVersion, aiGetVersionMinorTest ) {
+    EXPECT_EQ( aiGetVersionMinor(), 3 );
+}
+    
+TEST_F( utVersion, aiGetVersionMajorTest ) {
+    EXPECT_EQ( aiGetVersionMajor(), 3 );
+}
+
+TEST_F( utVersion, aiGetCompileFlagsTest ) {
+    EXPECT_NE( aiGetCompileFlags(), 0 );
+}
+
+TEST_F( utVersion, aiGetVersionRevisionTest ) {
+    EXPECT_NE( aiGetVersionRevision(), 0 );
+}