diff --git a/src/base/occ_handle.h b/src/base/occ_handle.h
index 1a4decbf..290bbc36 100644
--- a/src/base/occ_handle.h
+++ b/src/base/occ_handle.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <Standard_Handle.hxx>
+#include <Standard_Version.hxx>
 #include <utility> // For std::forward()
 
 namespace Mayo {
@@ -14,7 +15,7 @@ namespace Mayo {
 // Template alias for OpenCascade handle
 template<typename T> using OccHandle = opencascade::handle<T>;
 
-// Constructs an object of 'T' wrapped in an OpenCascade handle
+// Constructs an object of type 'T' wrapped in an OpenCascade handle
 // Note: Standard_Transient must be a base class of 'T'
 template<typename T, typename... Args>
 OccHandle<T> makeOccHandle(Args&&... args)
@@ -23,3 +24,16 @@ OccHandle<T> makeOccHandle(Args&&... args)
 }
 
 } // namespace Mayo
+
+#if OCC_VERSION_HEX < 0x070800
+namespace std {
+
+// Specialization of C++11 std::hash<> functor for opencascade::handle<> objects
+template<typename T> struct hash<opencascade::handle<T>> {
+    inline std::size_t operator()(const opencascade::handle<T>& hnd) const {
+        return hash<T*>{}(hnd.get());
+    }
+};
+
+} // namespace std
+#endif
diff --git a/src/base/tkernel_utils.h b/src/base/tkernel_utils.h
index 55678134..6be4fa04 100644
--- a/src/base/tkernel_utils.h
+++ b/src/base/tkernel_utils.h
@@ -9,7 +9,6 @@
 #include "occ_handle.h"
 
 #include <Quantity_Color.hxx>
-#include <Standard_Handle.hxx>
 #include <Standard_Version.hxx>
 #include <string>
 #include <string_view>
@@ -21,7 +20,6 @@
 #if OCC_VERSION_HEX >= OCC_VERSION_CHECK(7, 5, 0)
 #  include <Message_ProgressRange.hxx>
 #else
-#  include <Standard_Handle.hxx>
 class Message_ProgressIndicator;
 #endif
 
@@ -56,16 +54,3 @@ class TKernelUtils {
 };
 
 } // namespace Mayo
-
-#if OCC_VERSION_HEX < OCC_VERSION_CHECK(7, 8, 0)
-namespace std {
-
-// Specialization of C++11 std::hash<> functor for opencascade::handle<> objects
-template<typename T> struct hash<opencascade::handle<T>> {
-    inline std::size_t operator()(const opencascade::handle<T>& hnd) const {
-        return hash<T*>{}(hnd.get());
-    }
-};
-
-} // namespace std
-#endif
diff --git a/src/io_assimp/io_assimp_reader.h b/src/io_assimp/io_assimp_reader.h
index f443fb82..1d8f7ab0 100644
--- a/src/io_assimp/io_assimp_reader.h
+++ b/src/io_assimp/io_assimp_reader.h
@@ -7,7 +7,6 @@
 #pragma once
 
 #include "../base/io_reader.h"
-#include "../base/occ_handle.h"
 
 #include <assimp/Importer.hpp>