diff --git a/code/AssetLib/Assbin/AssbinFileWriter.cpp b/code/AssetLib/Assbin/AssbinFileWriter.cpp
index a879e637c..83a647a0b 100644
--- a/code/AssetLib/Assbin/AssbinFileWriter.cpp
+++ b/code/AssetLib/Assbin/AssbinFileWriter.cpp
@@ -60,10 +60,10 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <time.h>
 
-#ifdef _WIN32
+#if _MSC_VER
 #pragma warning(push)
 #pragma warning(disable : 4706)
-#endif // _WIN32
+#endif // _MSC_VER
 
 namespace Assimp {
 
@@ -825,8 +825,8 @@ void DumpSceneToAssbin(
     AssbinFileWriter fileWriter(shortened, compressed);
     fileWriter.WriteBinaryDump(pFile, cmd, pIOSystem, pScene);
 }
-#ifdef _WIN32
+#if _MSC_VER
 #pragma warning(pop)
-#endif // _WIN32
+#endif // _MSC_VER
 
 } // end of namespace Assimp
diff --git a/code/AssetLib/Assjson/cencode.h b/code/AssetLib/Assjson/cencode.h
index 6bf76724e..a7893c434 100644
--- a/code/AssetLib/Assjson/cencode.h
+++ b/code/AssetLib/Assjson/cencode.h
@@ -8,9 +8,9 @@ For details, see http://sourceforge.net/projects/libb64
 #ifndef BASE64_CENCODE_H
 #define BASE64_CENCODE_H
 
-#ifdef _WIN32
+#ifdef _MSC_VER
 #pragma warning(disable : 4127 )
-#endif // _WIN32
+#endif // _MSC_VER
 
 typedef enum
 {
diff --git a/code/AssetLib/glTF/glTFAsset.inl b/code/AssetLib/glTF/glTFAsset.inl
index 116f76535..eae56a64d 100644
--- a/code/AssetLib/glTF/glTFAsset.inl
+++ b/code/AssetLib/glTF/glTFAsset.inl
@@ -57,10 +57,10 @@ namespace glTF {
 
 namespace {
 
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(push)
 #    pragma warning(disable : 4706)
-#endif // _WIN32
+#endif // _MSC_VER
 
 //
 // JSON Value reading helpers
@@ -372,7 +372,7 @@ inline void Buffer::EncodedRegion_Mark(const size_t pOffset, const size_t pEncod
 
         char val[val_size];
 
-        ai_snprintf(val, val_size, "%llu", (long long)pOffset);
+        ai_snprintf(val, val_size, AI_SIZEFMT, pOffset);
         throw DeadlyImportError(std::string("GLTF: incorrect offset value (") + val + ") for marking encoded region.");
     }
 
@@ -382,7 +382,7 @@ inline void Buffer::EncodedRegion_Mark(const size_t pOffset, const size_t pEncod
 
         char val[val_size];
 
-        ai_snprintf(val, val_size, "%llu, %llu", (long long)pOffset, (long long)pEncodedData_Length);
+        ai_snprintf(val, val_size, AI_SIZEFMT, AI_SIZEFMT, pOffset, pEncodedData_Length);
         throw DeadlyImportError(std::string("GLTF: encoded region with offset/length (") + val + ") is out of range.");
     }
 
@@ -1412,8 +1412,8 @@ inline std::string Asset::FindUniqueID(const std::string &str, const char *suffi
     return id;
 }
 
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(pop)
-#endif // WIN32
+#endif // _MSC_VER
 
 } // namespace glTF
diff --git a/code/AssetLib/glTF/glTFAssetWriter.inl b/code/AssetLib/glTF/glTFAssetWriter.inl
index d8d2556fa..779c8ce58 100644
--- a/code/AssetLib/glTF/glTFAssetWriter.inl
+++ b/code/AssetLib/glTF/glTFAssetWriter.inl
@@ -43,10 +43,10 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <rapidjson/writer.h>
 #include <rapidjson/prettywriter.h>
 
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(push)
 #    pragma warning( disable : 4706)
-#endif // _WIN32
+#endif // _MSC_VER
 
 namespace glTF {
 
@@ -707,7 +707,7 @@ namespace glTF {
         w.WriteObjects(d);
     }
 
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(pop)
 #endif // _WIN32
 
diff --git a/code/AssetLib/glTF/glTFCommon.h b/code/AssetLib/glTF/glTFCommon.h
index b151918b6..f70780ed4 100644
--- a/code/AssetLib/glTF/glTFCommon.h
+++ b/code/AssetLib/glTF/glTFCommon.h
@@ -190,10 +190,10 @@ inline void CopyValue(const glTFCommon::mat4 &v, aiMatrix4x4 &o) {
     o.d4 = v[15];
 }
 
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(push)
 #    pragma warning(disable : 4310)
-#endif // _WIN32
+#endif // _MSC_VER
 
 inline std::string getCurrentAssetDir(const std::string &pFile) {
     std::string path = pFile;
@@ -204,9 +204,9 @@ inline std::string getCurrentAssetDir(const std::string &pFile) {
 
     return path;
 }
-#ifdef _WIN32
+#if _MSC_VER
 #    pragma warning(pop)
-#endif // _WIN32
+#endif // _MSC_VER
 
 namespace Util {
 
diff --git a/code/AssetLib/glTF/glTFExporter.cpp b/code/AssetLib/glTF/glTFExporter.cpp
index b85affc08..3edb87623 100644
--- a/code/AssetLib/glTF/glTFExporter.cpp
+++ b/code/AssetLib/glTF/glTFExporter.cpp
@@ -525,6 +525,10 @@ void ExportSkin(Asset& mAsset, const aiMesh* aimesh, Ref<Mesh>& meshRef, Ref<Buf
     delete[] vertexJointData;
 }
 
+#if __GNUC__
+#pragma GCC diagnostic ignored "-Wunused-but-set-variable"
+#endif // __GNUC__
+
 void glTFExporter::ExportMeshes()
 {
     // Not for
@@ -677,7 +681,7 @@ void glTFExporter::ExportMeshes()
 		{
 #ifdef ASSIMP_IMPORTER_GLTF_USE_OPEN3DGC
 			// Only one type of compression supported at now - Open3DGC.
-			//
+		//
 			o3dgc::BinaryStream bs;
 			o3dgc::SC3DMCEncoder<IndicesType> encoder;
 			o3dgc::IndexedFaceSet<IndicesType> comp_o3dgc_ifs;
@@ -793,6 +797,10 @@ void glTFExporter::ExportMeshes()
     }
 }
 
+#if __GNUC__
+#pragma GCC diagnostic pop
+#endif // __GNUC__
+
 /*
  * Export the root node of the node hierarchy.
  * Calls ExportNode for all children.
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index 142f39841..ca622d1e2 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -436,7 +436,7 @@ inline void Buffer::EncodedRegion_Mark(const size_t pOffset, const size_t pEncod
 
         char val[val_size];
 
-        ai_snprintf(val, val_size, "%llu", (long long)pOffset);
+        ai_snprintf(val, val_size, AI_SIZEFMT, pOffset);
         throw DeadlyImportError(std::string("GLTF: incorrect offset value (") + val + ") for marking encoded region.");
     }
 
@@ -446,7 +446,7 @@ inline void Buffer::EncodedRegion_Mark(const size_t pOffset, const size_t pEncod
 
         char val[val_size];
 
-        ai_snprintf(val, val_size, "%llu, %llu", (long long)pOffset, (long long)pEncodedData_Length);
+        ai_snprintf(val, val_size, AI_SIZEFMT, AI_SIZEFMT, pOffset, pEncodedData_Length);
         throw DeadlyImportError(std::string("GLTF: encoded region with offset/length (") + val + ") is out of range.");
     }
 
@@ -1042,10 +1042,10 @@ inline int Compare(const char *attr, const char (&str)[N]) {
     return (strncmp(attr, str, N - 1) == 0) ? N - 1 : 0;
 }
 
-#ifdef _WIN32
+#if _MSC_VER
 #pragma warning(push)
 #pragma warning(disable : 4706)
-#endif // _WIN32
+#endif // _MSC_VER
 
 inline bool GetAttribVector(Mesh::Primitive &p, const char *attr, Mesh::AccessorList *&v, int &pos) {
     if ((pos = Compare(attr, "POSITION"))) {
@@ -1723,8 +1723,8 @@ inline std::string Asset::FindUniqueID(const std::string &str, const char *suffi
     return id;
 }
 
-#ifdef _WIN32
-#pragma warning(pop)
-#endif // _WIN32
+#if _MSC_VER
+#   pragma warning(pop)
+#endif // _MSC_VER
 
 } // namespace glTF2
diff --git a/contrib/poly2tri/poly2tri/sweep/sweep.cc b/contrib/poly2tri/poly2tri/sweep/sweep.cc
index 9e3666001..23aeb6b57 100644
--- a/contrib/poly2tri/poly2tri/sweep/sweep.cc
+++ b/contrib/poly2tri/poly2tri/sweep/sweep.cc
@@ -36,10 +36,10 @@
 
 namespace p2t {
 
-#ifdef _WIN32
+#ifdef _MSC_VER
 #    pragma warning(push)
 #    pragma warning( disable : 4702 )
-#endif // _WIN32
+#endif // _MSC_VER
 
 // Triangulate simple polygon with holes
 void Sweep::Triangulate(SweepContext& tcx)
@@ -800,8 +800,8 @@ Sweep::~Sweep() {
 
 }
 
-#ifdef _WIN32
+#ifdef _MSC_VER
 #    pragma warning( pop )
-#endif // _WIN32
+#endif // _MSC_VER
 
 }
diff --git a/contrib/zip/src/zip.h b/contrib/zip/src/zip.h
index 807e328a8..2ebe9394d 100644
--- a/contrib/zip/src/zip.h
+++ b/contrib/zip/src/zip.h
@@ -15,9 +15,9 @@
 #include <string.h>
 #include <sys/types.h>
 
-#ifdef _WIN32
+#ifdef _MSC_VER
 #pragma warning(disable : 4127 )
-#endif //_WIN32
+#endif //_MSC_VER
 
 #ifdef __cplusplus
 extern "C" {
@@ -319,6 +319,10 @@ extern int zip_extract(const char *zipname, const char *dir,
 
 /** @} */
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif //_MSC_VER
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/assimp/StringUtils.h b/include/assimp/StringUtils.h
index 7e1cb4ce0..d848a6527 100644
--- a/include/assimp/StringUtils.h
+++ b/include/assimp/StringUtils.h
@@ -53,6 +53,12 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <stdarg.h>
 #include <cstdlib>
 
+#ifdef _MSC_VER
+#   define AI_SIZEFMT "%Iu"
+#else
+#   define AI_SIZEFMT "%zu"
+#endif
+
 ///	@fn		ai_snprintf
 ///	@brief	The portable version of the function snprintf ( C99 standard ), which works on visual studio compilers 2013 and earlier.
 ///	@param	outBuf		The buffer to write in
@@ -87,6 +93,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 		return count;
 	}
 
+#elif defined(__MINGW32__)
+#   define ai_snprintf __mingw_snprintf
 #else
 #   define ai_snprintf snprintf
 #endif
@@ -150,7 +158,7 @@ std::string DecimalToHexa( T toConvert ) {
 ///	@param	g   aiColor.g
 ///	@param	b   aiColor.b
 ///	@param	a   aiColor.a
-///	@param	with_head   # 
+///	@param	with_head   #
 ///	@return	The hexadecimal string, is empty in case of an error.
 AI_FORCE_INLINE std::string Rgba2Hex(int r, int g, int b, int a, bool with_head) {
 	std::stringstream ss;
@@ -158,7 +166,7 @@ AI_FORCE_INLINE std::string Rgba2Hex(int r, int g, int b, int a, bool with_head)
 		ss << "#";
     }
 	ss << std::hex << (r << 24 | g << 16 | b << 8 | a);
-	
+
     return ss.str();
 }