diff --git a/mayo.pro b/mayo.pro
index 1a876640..7cf8316a 100644
--- a/mayo.pro
+++ b/mayo.pro
@@ -229,6 +229,12 @@ defined(ASSIMP_IS_ON, var) {
     HEADERS += $$files(src/io_assimp/*.h)
     SOURCES += $$files(src/io_assimp/*.cpp)
 
+    ASSIMP_VERSION_FILE_CONTENTS = $$cat($$ASSIMP_INC_DIR/assimp/version.h, lines)
+    ASSIMP_aiGetVersionPatch = $$find(ASSIMP_VERSION_FILE_CONTENTS, ASSIMP_API\s+unsigned\s+int\s+aiGetVersionPatch)
+    !isEmpty(ASSIMP_aiGetVersionPatch) {
+         DEFINES += HAVE_ASSIMP_aiGetVersionPatch
+    }
+
     INCLUDEPATH += $$ASSIMP_INC_DIR
     LIBS += -L$$ASSIMP_LIB_DIR
     win32 {
diff --git a/src/io_assimp/io_assimp.cpp b/src/io_assimp/io_assimp.cpp
index 17300e0a..2230e62d 100644
--- a/src/io_assimp/io_assimp.cpp
+++ b/src/io_assimp/io_assimp.cpp
@@ -62,14 +62,20 @@ std::string_view AssimpLib::strVersion()
             addFlagIfDefined(ASSIMP_CFLAGS_DEBUG, "debug");
             addFlagIfDefined(ASSIMP_CFLAGS_NOBOOST, "no-boost");
             addFlagIfDefined(ASSIMP_CFLAGS_SINGLETHREADED, "single-threaded");
+#ifdef ASSIMP_CFLAGS_DOUBLE_SUPPORT
             addFlagIfDefined(ASSIMP_CFLAGS_DOUBLE_SUPPORT, "double-support");
+#endif
         }
 
         str += std::to_string(aiGetVersionMajor())
                + "." + std::to_string(aiGetVersionMinor())
+#ifdef HAVE_ASSIMP_aiGetVersionPatch
                + "." + std::to_string(aiGetVersionPatch())
+#else
+               + ".?"
+#endif
                + " rev:" + std::to_string(aiGetVersionRevision())
-               + " branch:" + strBranchName
+               + " branch:" + (!strBranchName.empty() ? strBranchName : "?")
                + " flags:" + strCompileFlags
             ;
     }
diff --git a/src/io_assimp/io_assimp_reader.cpp b/src/io_assimp/io_assimp_reader.cpp
index e7d39af4..5a41434c 100644
--- a/src/io_assimp/io_assimp_reader.cpp
+++ b/src/io_assimp/io_assimp_reader.cpp
@@ -13,6 +13,7 @@
 #include "../base/math_utils.h"
 #include "../base/mesh_utils.h"
 #include "../base/messenger.h"
+#include "../base/occ_handle.h"
 #include "../base/property.h"
 #include "../base/string_conv.h"
 #include "../base/task_progress.h"
@@ -226,10 +227,10 @@ class AssimpReader::Properties : public PropertyGroup {
 bool AssimpReader::readFile(const FilePath& filepath, TaskProgress* progress)
 {
     m_vecTriangulation.clear();
-    m_vecEmbeddedTexture.clear();
     m_vecMaterial.clear();
     m_mapMaterialLabel.clear();
     m_mapNodeData.clear();
+    m_mapEmbeddedTexture.clear();
     m_mapFileTexture.clear();
 
     const unsigned flags =
@@ -289,11 +290,9 @@ bool AssimpReader::readFile(const FilePath& filepath, TaskProgress* progress)
         }
     }
 
-    m_vecEmbeddedTexture.resize(m_scene->mNumTextures);
-    std::fill(m_vecEmbeddedTexture.begin(), m_vecEmbeddedTexture.end(), nullptr);
     for (unsigned i = 0; i < m_scene->mNumTextures; ++i) {
         const aiTexture* texture = m_scene->mTextures[i];
-        m_vecEmbeddedTexture.at(i) = createOccTexture(texture);
+        m_mapEmbeddedTexture.insert({ texture, createOccTexture(texture) });
     }
 
     m_vecMaterial.resize(m_scene->mNumMaterials);
@@ -369,20 +368,21 @@ void AssimpReader::applyProperties(const PropertyGroup* group)
 }
 
 Handle(Image_Texture) AssimpReader::findOccTexture(
-    const aiString& strFilepath, const FilePath& modelFilepath
+    const std::string& strFilepath, const FilePath& modelFilepath
     )
 {
     // Texture might be embedded
     {
-        auto [texture, textureIndex] = m_scene->GetEmbeddedTextureAndIndex(strFilepath.C_Str());
-        if (textureIndex != -1)
-            return m_vecEmbeddedTexture.at(textureIndex);
+        // Note: aiScene::GetEmbeddedTextureAndIndex() isn't available for version < 5.1
+        const aiTexture* texture = m_scene->GetEmbeddedTexture(strFilepath.c_str());
+        Handle(Image_Texture) occTexture = Cpp::findValue(texture, m_mapEmbeddedTexture);
+        if (occTexture)
+	    return occTexture;
     }
 
     // Texture might have already been loaded from file
-    const FilePath textureFilepath = filepathFrom(std::string_view{ strFilepath.C_Str() });
     {
-        Handle(Image_Texture) texture = CppUtils::findValue(textureFilepath, m_mapFileTexture);
+        Handle(Image_Texture) texture = CppUtils::findValue(strFilepath, m_mapFileTexture);
         if (texture)
             return texture;
     }
@@ -390,6 +390,7 @@ Handle(Image_Texture) AssimpReader::findOccTexture(
     // Fallback: load texture from filepath
 
     // Define texture "candidate" filepaths that will be tried
+    const FilePath textureFilepath = filepathFrom(strFilepath);
     const FilePath textureFilepathCandidates[] = {
         textureFilepath,
         modelFilepath.parent_path() / textureFilepath,
@@ -408,13 +409,13 @@ Handle(Image_Texture) AssimpReader::findOccTexture(
     if (ptrTextureFilepath) {
         Handle(Image_Texture) texture = new Image_Texture(filepathTo<TCollection_AsciiString>(*ptrTextureFilepath));
         // Cache texture
-        m_mapFileTexture.insert({ textureFilepath, texture });
+        m_mapFileTexture.insert({ strFilepath, texture });
         return texture;
     }
 
     // Report warning "texture not found"
     MessageStream msgWarning = this->messenger()->warning();
-    msgWarning << fmt::format(AssimpReaderI18N::textIdTr("Texture not found: {}\nTried:"), textureFilepath.u8string());
+    msgWarning << fmt::format(AssimpReaderI18N::textIdTr("Texture not found: {}\nTried:"), strFilepath);
     for (const FilePath& fp : textureFilepathCandidates)
         msgWarning << "\n    " << filepathCanonical(fp).make_preferred().u8string();
 
@@ -441,8 +442,10 @@ Handle(XCAFDoc_VisMaterial) AssimpReader::createOccVisMaterial(
 
     // Set name
     {
-        std::string_view matName{ material->GetName().data, material->GetName().length };
-        mat->SetRawName(string_conv<Handle(TCollection_HAsciiString)>(matName));
+        aiString matName;
+        material->Get(AI_MATKEY_NAME, matName);
+        std::string_view vMatName{ matName.C_Str(), matName.length };
+        mat->SetRawName(string_conv<Handle(TCollection_HAsciiString)>(vMatName));
     }
 
     // Backface culling
@@ -492,6 +495,11 @@ Handle(XCAFDoc_VisMaterial) AssimpReader::createOccVisMaterial(
         return fnUpdateDefinedFlag(ptrDefinedFlag, res);
     };
 
+    // Helper function around AssimpReader::findOccTexture()
+    auto fnFindOccTexture = [=](const aiString& strTexture) {
+        return this->findOccTexture(strTexture.C_Str(), modelFilepath);
+    };
+
     // Common
     XCAFDoc_VisMaterialCommon matCommon;
     matCommon.IsDefined = false;
@@ -531,7 +539,7 @@ Handle(XCAFDoc_VisMaterial) AssimpReader::createOccVisMaterial(
     {
         aiString texDiffuse;
         if (fnGetTexture(aiTextureType_DIFFUSE, &texDiffuse, &matCommon.IsDefined))
-            matCommon.DiffuseTexture = this->findOccTexture(texDiffuse, modelFilepath);
+            matCommon.DiffuseTexture = fnFindOccTexture(texDiffuse);
     }
 
     // PBR
@@ -541,26 +549,28 @@ Handle(XCAFDoc_VisMaterial) AssimpReader::createOccVisMaterial(
     {
         aiString strTexture;
         if (fnGetTexture(aiTextureType_BASE_COLOR, &strTexture, &matPbr.IsDefined))
-            matPbr.BaseColorTexture = this->findOccTexture(strTexture, modelFilepath);
+            matPbr.BaseColorTexture = fnFindOccTexture(strTexture);
 
         if (fnGetTexture(aiTextureType_METALNESS, &strTexture))
-            matPbr.MetallicRoughnessTexture = this->findOccTexture(strTexture, modelFilepath);
+            matPbr.MetallicRoughnessTexture = fnFindOccTexture(strTexture);
 
         if (fnGetTexture(aiTextureType_EMISSION_COLOR, &strTexture, &matPbr.IsDefined))
-            matPbr.EmissiveTexture = this->findOccTexture(strTexture, modelFilepath);
+            matPbr.EmissiveTexture = fnFindOccTexture(strTexture);
 
         if (fnGetTexture(aiTextureType_AMBIENT_OCCLUSION, &strTexture, &matPbr.IsDefined))
-            matPbr.OcclusionTexture = this->findOccTexture(strTexture, modelFilepath);
+            matPbr.OcclusionTexture = fnFindOccTexture(strTexture);
 
         if (fnGetTexture(aiTextureType_NORMALS, &strTexture, &matPbr.IsDefined))
-            matPbr.NormalTexture = this->findOccTexture(strTexture, modelFilepath);
+            matPbr.NormalTexture = fnFindOccTexture(strTexture);
     }
 
+#ifdef AI_MATKEY_BASE_COLOR
     {
         aiColor4D color;
         if (fnGetColor4D(AI_MATKEY_BASE_COLOR, &color, &matPbr.IsDefined))
             matPbr.BaseColor = Quantity_ColorRGBA(toOccColor(color), color.a);
     }
+#endif
 
     {
         // TODO Handle EmissiveFactor
@@ -568,11 +578,15 @@ Handle(XCAFDoc_VisMaterial) AssimpReader::createOccVisMaterial(
 
     {
         ai_real value;
+#ifdef AI_MATKEY_METALLIC_FACTOR
         if (fnGetReal(AI_MATKEY_METALLIC_FACTOR, &value, &matPbr.IsDefined))
             matPbr.Metallic = std::clamp(value, 0.f, 1.f);
+#endif
 
+#ifdef AI_MATKEY_ROUGHNESS_FACTOR
         if (fnGetReal(AI_MATKEY_ROUGHNESS_FACTOR, &value, &matPbr.IsDefined))
             matPbr.Roughness = std::clamp(value, 0.f, 1.f);
+#endif
 
         if (fnGetReal(AI_MATKEY_REFRACTI, &value, &matPbr.IsDefined)) {
             // Refraction index must be in range [1.0, 3.0]
diff --git a/src/io_assimp/io_assimp_reader.h b/src/io_assimp/io_assimp_reader.h
index c1da51f9..20fbc223 100644
--- a/src/io_assimp/io_assimp_reader.h
+++ b/src/io_assimp/io_assimp_reader.h
@@ -8,7 +8,6 @@
 
 #include "../base/document_ptr.h"
 #include "../base/io_reader.h"
-#include "../base/occ_handle.h"
 #include "../base/tkernel_utils.h"
 
 #include <assimp/Importer.hpp>
@@ -41,7 +40,7 @@ class AssimpReader : public Reader {
     // Create OpenCascade texture object
     // Parameter 'strFilepath' is the filepath to the texture as specified by the assimp material
     // Parameter 'modelFilepath' is the filepath to the 3D model being imported with Reader::readFile()
-    Handle(Image_Texture) findOccTexture(const aiString& strFilepath, const FilePath& modelFilepath);
+    Handle(Image_Texture) findOccTexture(const std::string& strFilepath, const FilePath& modelFilepath);
 
     // Create XCAFDoc_VisMaterial from assimp material
     // Parameter 'modelFilepath' is the filepath to the 3D model being imported with Reader::readFile()
@@ -64,11 +63,11 @@ class AssimpReader : public Reader {
     const aiScene* m_scene = nullptr;
 
     std::vector<Handle(Poly_Triangulation)> m_vecTriangulation;
-    std::vector<Handle(Image_Texture)> m_vecEmbeddedTexture;
     std::vector<Handle(XCAFDoc_VisMaterial)> m_vecMaterial;
     std::unordered_map<Handle(XCAFDoc_VisMaterial), TDF_Label> m_mapMaterialLabel;
     std::unordered_map<const aiNode*, aiNodeData> m_mapNodeData;
-    std::unordered_map<FilePath, Handle(Image_Texture)> m_mapFileTexture;
+    std::unordered_map<const aiTexture*, Handle(Image_Texture)> m_mapEmbeddedTexture;
+    std::unordered_map<std::string, Handle(Image_Texture)> m_mapFileTexture;
 };
 
 } // namespace IO