diff --git a/nix/build-all.py b/nix/build-all.py
index 96f8f86cb0..09773f5e84 100644
--- a/nix/build-all.py
+++ b/nix/build-all.py
@@ -81,7 +81,7 @@ ADD_COMMIT_SHA = os.getenv("ADD_COMMIT_SHA")
 PYTHON_VERSIONS = ["3.9.11", "3.10.3", "3.11.8", "3.12.1"]
 JSON_VERSION = "v3.6.1"
 OCE_VERSION = "0.18.3"
-OCCT_VERSION = "7.7.1"
+OCCT_VERSION = "7.5.3"
 BOOST_VERSION = "1.80.0"
 PCRE_VERSION = "8.41"
 LIBXML2_VERSION = "2.9.11"
diff --git a/win/build-deps.cmd b/win/build-deps.cmd
index 0e6ddeb549..1a669eda49 100644
--- a/win/build-deps.cmd
+++ b/win/build-deps.cmd
@@ -169,7 +169,7 @@ cd "%DEPS_DIR%"
 :: VERSIONS
 set HDF5_VERSION=1.8.22
 set HDF5_VERSION_MAJOR=1.8
-set OCCT_VERSION=7.7.1
+set OCCT_VERSION=7.5.3
 :: NOTE If updating the default Python version, change PY_VER_MAJOR_MINOR accordingly in run-cmake.bat
 set PYTHON_VERSION=3.11.7