diff --git a/code/AssetLib/IFC/IFCOpenings.cpp b/code/AssetLib/IFC/IFCOpenings.cpp
index 74200195b..6b8b565c2 100644
--- a/code/AssetLib/IFC/IFCOpenings.cpp
+++ b/code/AssetLib/IFC/IFCOpenings.cpp
@@ -1476,7 +1476,7 @@ std::vector<IfcVector2> GetContourInPlane2D(std::shared_ptr<TempMesh> mesh,IfcMa
     return contour;
 }
 
-const float close{ ai_epsilon };
+const ai_real close{ ai_epsilon };
 
 static bool isClose(IfcVector2 first,IfcVector2 second) {
     auto diff = (second - first);
diff --git a/code/AssetLib/Obj/ObjFileParser.cpp b/code/AssetLib/Obj/ObjFileParser.cpp
index 1786c0d9f..4e50d5dae 100644
--- a/code/AssetLib/Obj/ObjFileParser.cpp
+++ b/code/AssetLib/Obj/ObjFileParser.cpp
@@ -55,7 +55,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace Assimp {
 
-constexpr char ObjFileParser::DEFAULT_MATERIAL[];
+constexpr const char ObjFileParser::DEFAULT_MATERIAL[];
 
 ObjFileParser::ObjFileParser() :
         m_DataIt(),
diff --git a/code/AssetLib/Obj/ObjFileParser.h b/code/AssetLib/Obj/ObjFileParser.h
index fbd2f2c89..1bf11a0c8 100644
--- a/code/AssetLib/Obj/ObjFileParser.h
+++ b/code/AssetLib/Obj/ObjFileParser.h
@@ -141,7 +141,7 @@ private:
     // because the class contains pointer to allocated memory
 
     /// Default material name
-    static constexpr char DEFAULT_MATERIAL[] = AI_DEFAULT_MATERIAL_NAME;
+    static constexpr const char DEFAULT_MATERIAL[] = AI_DEFAULT_MATERIAL_NAME;
     //! Iterator to current position in buffer
     DataArrayIt m_DataIt;
     //! Iterator to end position of buffer
diff --git a/code/AssetLib/glTF/glTFAsset.inl b/code/AssetLib/glTF/glTFAsset.inl
index 2b76a30ab..1f4544156 100644
--- a/code/AssetLib/glTF/glTFAsset.inl
+++ b/code/AssetLib/glTF/glTFAsset.inl
@@ -53,9 +53,9 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 using namespace Assimp;
-using namespace glTFCommon;
 
 namespace glTF {
+using namespace glTFCommon;
 
 #if _MSC_VER
 #pragma warning(push)
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index a74866e6c..db47915d6 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -82,9 +82,21 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 // clang-format on
 
 using namespace Assimp;
-using namespace glTFCommon;
 
 namespace glTF2 {
+using glTFCommon::FindStringInContext;
+using glTFCommon::FindNumberInContext;
+using glTFCommon::FindUIntInContext;
+using glTFCommon::FindArrayInContext;
+using glTFCommon::FindObjectInContext;
+using glTFCommon::FindExtensionInContext;
+using glTFCommon::MemberOrDefault;
+using glTFCommon::ReadMember;
+using glTFCommon::FindMember;
+using glTFCommon::FindObject;
+using glTFCommon::FindUInt;
+using glTFCommon::FindArray;
+using glTFCommon::FindArray;
 
 namespace {
 
diff --git a/include/assimp/Bitmap.h b/include/assimp/Bitmap.h
index 6a614f7cf..94dd0b81b 100644
--- a/include/assimp/Bitmap.h
+++ b/include/assimp/Bitmap.h
@@ -78,11 +78,11 @@ protected:
 
         // We define the struct size because sizeof(Header) might return a wrong result because of structure padding.
         static constexpr std::size_t header_size =
-            sizeof(type) +
-            sizeof(size) +
-            sizeof(reserved1) +
-            sizeof(reserved2) +
-            sizeof(offset);
+            sizeof(uint16_t) +
+            sizeof(uint32_t) +
+            sizeof(uint16_t) +
+            sizeof(uint16_t) +
+            sizeof(uint32_t);
     };
 
     struct DIB {
@@ -100,17 +100,17 @@ protected:
 
         // We define the struct size because sizeof(DIB) might return a wrong result because of structure padding.
         static constexpr std::size_t dib_size =
-            sizeof(size) +
-            sizeof(width) +
-            sizeof(height) +
-            sizeof(planes) +
-            sizeof(bits_per_pixel) +
-            sizeof(compression) +
-            sizeof(image_size) +
-            sizeof(x_resolution) +
-            sizeof(y_resolution) +
-            sizeof(nb_colors) +
-            sizeof(nb_important_colors);
+            sizeof(uint32_t) +
+            sizeof(int32_t) +
+            sizeof(int32_t) +
+            sizeof(uint16_t) +
+            sizeof(uint16_t) +
+            sizeof(uint32_t) +
+            sizeof(uint32_t) +
+            sizeof(int32_t) +
+            sizeof(int32_t) +
+            sizeof(uint32_t) +
+            sizeof(uint32_t);
     };
 
     static constexpr std::size_t mBytesPerPixel = 4;
diff --git a/include/assimp/material.inl b/include/assimp/material.inl
index 0b30a6839..cdf272201 100644
--- a/include/assimp/material.inl
+++ b/include/assimp/material.inl
@@ -157,7 +157,7 @@ AI_FORCE_INLINE
         case aiPTI_Float:
         case aiPTI_Double: {
             // Read as float and cast to bool
-            float value = 0.0f;
+            ai_real value = 0.0f;
             if (AI_SUCCESS == ::aiGetMaterialFloat(this, pKey, type, idx, &value)) {
                 pOut = static_cast<bool>(value);
                 return AI_SUCCESS;