diff --git a/trunk/PKGBUILD b/trunk/PKGBUILD
index 1f3198a7b652..df66ca356c42 100644
--- a/trunk/PKGBUILD
+++ b/trunk/PKGBUILD
@@ -7,9 +7,9 @@
 # Contributor: Michele Mocciola <mickele>
 
 pkgname=opencascade
-pkgver=7.6.0
-_pkgver="V${pkgver//./_}"
+pkgver=7.5.3
 pkgrel=1
+epoch=1
 pkgdesc="SDK intended for development of applications dealing with 3D CAD data"
 arch=('x86_64')
 url="https://www.opencascade.org"
@@ -23,6 +23,7 @@ depends=(
   'vtk'
 )
 makedepends=(
+  'git'
   'adios2'
   'boost'
   'cmake'
@@ -42,32 +43,43 @@ makedepends=(
   'unixodbc'
   'utf8cpp'
 )
+_commit='fecb042498514186bd37fa621cdcf09eb61899a3' # V7_5_3
 source=(
-  "$pkgname-$pkgver.tar.gz::https://git.dev.opencascade.org/gitweb/?p=occt.git;a=snapshot;h=refs/tags/$_pkgver;sf=tgz"
+  "$pkgname::git+https://git.dev.opencascade.org/repos/occt.git#commit=$_commit"
   'opencascade.sh'
   'fix-install-dir-references.patch'
   'cmake-fix-variable.patch'
   'skip-license-installation.patch'
+  'vtk9.patch'
   'opencascade-tbb-2021.patch'
 )
-sha512sums=('6839eb6641b9e0752474fce11cf1756223067febe0f5bcd5db249e3eccef29517a6952c124aae818220b6360070a792dacd1b0b4ce970b8351ce38598f31b4be'
+sha512sums=('SKIP'
             'a7516028e55fd303dc1cfb61b75c9cb209d431d854b4d1c58f9c19df8ecee9d79da5c8745676c68a2de0980652de4c4d1c5a927c25db1e5146fb1f1f43c5906b'
-            'fc5eefe2a3ee11f77ee7c304d42d3b32dc5c86050879b9ae5f02da6242a87872aa5da7ae40a961a0a799dc241a81394f8a3ca022dd14d35bc2a61599eed3f983'
+            '826b8572eb298696b0005701bca5ad0406151ec7aa88cd53f9ffaf23a306003a48416b6d120dc5c7e3c14d290e9a15ba93943c4846b6fee8bdb06bd699904f79'
             'ad6ce2f52462989bd990b52fd5428f3e5cbd4fb15c38d92c0e0954e6afc3368fca961b92efead8e8957213352fb87a469e1bfaccaf14b484351acc0a0bc10485'
             'fd8499793b12e4e59420f63351fef9599c3976d307979beea2681b873a340ae673ba643a7060c74bec1dd4801954c99f8f1f1a8bcc3baa3db9cbfce32153675e'
-            '24d81b4db35267464baedffd552d7b846871f64afaff46d92bf309c8113f20d8b575975946de2f1ff561455100541b5a5a6c44f377aa4c3c63f1da9930e34d4f')
-b2sums=('c16cd096f20e90267a00b6be21b17b22b491cf5d9aa1a311d64d7707042dc88380c60ececceb6728dbcdd4ff56a67558144292950e11518b21cbc49ace4e88cd'
+            '2725df308f23f11faa664391174a4f21bec13328c7b33ba065bfd28988a4bd815c86849d8815fcdb8f6ed5dd1d7b1a38ded1675c1c08dec1276367fc571917c0'
+            '1d6e0321d0b54caf0130b2c6f81dbbdc621913ffa1c38e464d9be65088085fc831ac69788393911a1dd269f4296c93d26c1706d262537912459eb795bc4f742b')
+b2sums=('SKIP'
         'da9db038ed2348d2d7736505eda2f40fe52c836bcedb74d9f369cc53f7d40a330bd87d6aedd773863745cd46e4dbe5876acda2d2d60177f00d5db9cae4f1f102'
-        '4fae705cd68a259a831df5cd83c72a8a3e2508a99dcc4cb572164bcbcf0a15f50fa803e520793249043edf78f93eceebfa2311fed5e0391d64476b31ccbec079'
+        'a56cedf43366d52a81301d653834942fb74a4feafb4ac57923448d42164f060f1874a2180688e482c0dac70a5ea1d2fb53d4410503f22626ff5d2bab405a352f'
         'bb98b2b53a9a97ae15a353a9dbcc6d92a97ddaa56af0610cefe9de3a4b84c4a6021d9396f7e270c1d379278df069dbf90f9771db64947e52d38ad36bc3c6f913'
         'da815c14ad3a8283c4f3cf41b6b19b40408798f64374b909c776f5ab22ee9ccfc2653c09b33c7b550a138007ff2b36b40d742c9fddc7c1ea499dfe58e59f57ea'
-        'f996126927c0f418cf6592300db7f9e8c4c8a899cb4a06f2eb37c7849f40176fc2d81de421ec346aaec5a99243388a466f75a2689ac7e6177ac9092802a31877')
+        'af240c6f9ba62f336f59caa7cff2bb40915137a02f5b03ee54fa17a5ef27d0411800aa981090a17b3d7c780835625bd4b263975eb100aa71fdc58eb1806916ea'
+        '905d13cf39225c1148e215ad37ab601dfe649f3d4d66b099ae028cdf8fb2a92534e7b14361238566c295ae443a3a3dfeb5f69ab51987b952604eb53821fa92cd')
+
+pkgver() {
+  cd "$pkgname"
+  git describe --tags | sed -e "s/^V//" -e "s/_/./g" -e "s/p/./"
+}
 
 prepare() {
-  cd "occt-$_pkgver"
+  cd "$pkgname"
 
   patch -p1 -i ../fix-install-dir-references.patch
   patch -p1 -i ../cmake-fix-variable.patch
+  patch -p1 -i ../vtk9.patch # Fix build with VTK 9 https://gitlab.kitware.com/vtk/vtk/-/issues/18240
+  git cherry-pick -n 5e7632824302761b84cfceb5bfb2241d906d0eb4 # Fix build of FreeCAD
   patch -p1 -i ../skip-license-installation.patch
   patch -p1 -i ../opencascade-tbb-2021.patch # Fix build with TBB 2021
 }
@@ -75,11 +87,10 @@ prepare() {
 build() {
   cmake \
     -B build \
-    -S "occt-$_pkgver" \
+    -S "$pkgname" \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=/usr \
     -DBUILD_RELEASE_DISABLE_EXCEPTIONS=OFF \
-    -DUSE_GL2PS=ON \
     -DUSE_FREEIMAGE=ON \
     -DUSE_FFMPEG=ON \
     -DUSE_VTK=ON \
@@ -94,12 +105,12 @@ package() {
   DESTDIR="$pkgdir" cmake --install build
 
   # environment variables (adapted from adm/templates/env.sh)
-  install -vDm755 -t "$pkgdir/etc/profile.d" opencascade.sh
+  install -vDm644 -t "$pkgdir/etc/profile.d" opencascade.sh
 
   # remove unnecessary shell scripts
   rm -v "$pkgdir/usr/bin/"*.sh
 
-  cd "occt-$_pkgver"
+  cd "$pkgname"
 
   # licenses
   install -vDm755 -t "$pkgdir/usr/share/licenses/$pkgname" \
diff --git a/trunk/fix-install-dir-references.patch b/trunk/fix-install-dir-references.patch
index 98fab58b0366..ae94e4bcdb9f 100644
--- a/trunk/fix-install-dir-references.patch
+++ b/trunk/fix-install-dir-references.patch
@@ -9,8 +9,6 @@
  
  foreach (OCCT_MODULE ${OCCT_MODULES})
    if (BUILD_MODULE_${OCCT_MODULE})
-diff --git a/adm/cmake/occt_macros.cmake b/adm/cmake/occt_macros.cmake
-index 0a387945..e3f13923 100644
 --- a/adm/cmake/occt_macros.cmake
 +++ b/adm/cmake/occt_macros.cmake
 @@ -592,7 +592,7 @@ macro (OCCT_UPDATE_TARGET_FILE)
diff --git a/trunk/opencascade-tbb-2021.patch b/trunk/opencascade-tbb-2021.patch
index fae8982e3e25..21529058da0b 100644
--- a/trunk/opencascade-tbb-2021.patch
+++ b/trunk/opencascade-tbb-2021.patch
@@ -1,5 +1,3 @@
-diff --git a/src/OSD/OSD_Parallel_TBB.cxx b/src/OSD/OSD_Parallel_TBB.cxx
-index 2344a6ca2..e1a3d89de 100644
 --- a/src/OSD/OSD_Parallel_TBB.cxx
 +++ b/src/OSD/OSD_Parallel_TBB.cxx
 @@ -25,7 +25,7 @@ Standard_DISABLE_DEPRECATION_WARNINGS
diff --git a/trunk/vtk9.patch b/trunk/vtk9.patch
new file mode 100644
index 000000000000..943be2a892d9
--- /dev/null
+++ b/trunk/vtk9.patch
@@ -0,0 +1,31 @@
+--- a/src/IVtkDraw/IVtkDraw_HighlightAndSelectionPipeline.hxx
++++ b/src/IVtkDraw/IVtkDraw_HighlightAndSelectionPipeline.hxx
+@@ -23,6 +23,7 @@
+ 
+ // prevent disabling some MSVC warning messages by VTK headers 
+ #include <Standard_WarningsDisable.hxx>
++#undef AllValues
+ #include <vtkActor.h>
+ #include <vtkPolyData.h>
+ #include <vtkPolyDataMapper.h>
+--- a/src/IVtkVTK/IVtkVTK_ShapeData.hxx
++++ b/src/IVtkVTK/IVtkVTK_ShapeData.hxx
+@@ -23,6 +23,7 @@
+ #include <vtkPolyData.h>
+ #include <vtkSmartPointer.h>
+ #include <vtkIdTypeArray.h>
++#include <vtkVersion.h>
+ #include <Standard_WarningsRestore.hxx>
+ 
+ class vtkIdTypeArray;
+--- a/src/InterfaceGraphic/InterfaceGraphic.hxx
++++ b/src/InterfaceGraphic/InterfaceGraphic.hxx
+@@ -40,6 +40,8 @@
+ #include <X11/Xatom.h>
+ #include <GL/glx.h>
+ 
++#undef AllValues
++
+ #endif
+ 
+ #endif // __INTERFACE_GRAPHIC_HXX