diff --git a/nix/build-all.py b/nix/build-all.py
index d02c67c7bc..a697913fdb 100644
--- a/nix/build-all.py
+++ b/nix/build-all.py
@@ -82,19 +82,11 @@ PROJECT_NAME="IfcOpenShell"
 PYTHON_VERSIONS=["2.7.16", "3.2.6", "3.3.6", "3.4.6", "3.5.3", "3.6.2", "3.7.3", "3.8.6", "3.9.1"]
 JSON_VERSION="v3.6.1"
 OCE_VERSION="0.18"
-# OCCT_VERSION="7.1.0"
-# OCCT_HASH="89aebde"
-# OCCT_VERSION="7.2.0"
-# OCCT_HASH="88af392"
-OCCT_VERSION="7.3.0p3"
+OCCT_VERSION="7.5.3"
 BOOST_VERSION="1.71.0"
-#PCRE_VERSION="8.39"
 PCRE_VERSION="8.41"
-#LIBXML2_VERSION="2.9.3"
 LIBXML2_VERSION="2.9.9"
 SWIG_VERSION="3.0.12"
-#SWIG_VERSION="4.0.0"
-#OPENCOLLADA_VERSION="v1.6.63"
 OPENCOLLADA_VERSION="v1.6.68"
 HDF5_VERSION="1.8.22"
 
diff --git a/win/build-deps.cmd b/win/build-deps.cmd
index 49d8f21d95..995a693185 100644
--- a/win/build-deps.cmd
+++ b/win/build-deps.cmd
@@ -267,7 +267,7 @@ IF NOT %ERRORLEVEL%==0 GOTO :Error
 
 if %IFCOS_USE_OCCT%==FALSE goto :OCE
 :OCCT
-set OCCT_VERSION=7.3.0p3
+set OCCT_VERSION=7.5.3
 SET OCCT_VER=V%OCCT_VERSION:.=_%
 
 set OCC_INCLUDE_DIR=%INSTALL_DIR%\opencascade-%OCCT_VERSION%\inc>>"%~dp0\%BUILD_DEPS_CACHE_PATH%"
diff --git a/win/patches/V7_5_2.patch b/win/patches/V7_5_3.patch
similarity index 100%
rename from win/patches/V7_5_2.patch
rename to win/patches/V7_5_3.patch