diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index ef6c3ac671..4de0ca4698 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -398,6 +398,10 @@ if(USE_MMAP)
     endif()
 endif()
 
+# 3.3.9 is the version currently used on the Windows build.
+# 3.4.0 is the version shipped with Ubuntu 22.04.
+set(EIGEN_MIN_VERSION 3.3.9)
+
 # 1.74 is the version shipped with Ubuntu 22.04.
 set(BOOST_MIN_VERSION 1.74)
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 14)
diff --git a/cmake/FindEigen3.cmake b/cmake/FindEigen3.cmake
index e886310e89..8e4c9a961d 100644
--- a/cmake/FindEigen3.cmake
+++ b/cmake/FindEigen3.cmake
@@ -10,11 +10,25 @@
 UNIFY_ENVVARS_AND_CACHE(EIGEN_DIR)
 
 if(EXISTS "${EIGEN_DIR}")
+    file(STRINGS "${EIGEN_DIR}/Eigen/src/Core/util/Macros.h" eigen_version_world_line REGEX "^#define EIGEN_WORLD_VERSION")
+    file(STRINGS "${EIGEN_DIR}/Eigen/src/Core/util/Macros.h" eigen_version_major_line REGEX "^#define EIGEN_MAJOR_VERSION")
+    file(STRINGS "${EIGEN_DIR}/Eigen/src/Core/util/Macros.h" eigen_version_minor_line REGEX "^#define EIGEN_MINOR_VERSION")
+    string(REGEX REPLACE "^#define EIGEN_WORLD_VERSION ([0-9]+)$" "\\1" eigen_version_world "${eigen_version_world_line}")
+    string(REGEX REPLACE "^#define EIGEN_MAJOR_VERSION ([0-9]+)$" "\\1" eigen_version_major "${eigen_version_major_line}")
+    string(REGEX REPLACE "^#define EIGEN_MINOR_VERSION ([0-9]+)$" "\\1" eigen_version_minor "${eigen_version_minor_line}")
+    set(Eigen3_VERSION "${eigen_version_world}.${eigen_version_major}.${eigen_version_minor}")
+
+    include(FindPackageHandleStandardArgs)
+    find_package_handle_standard_args(Eigen3
+        REQUIRED_VARS EIGEN_DIR
+        VERSION_VAR Eigen3_VERSION
+    )
+
     # Mimic Eigen3Config.cmake target.
     add_library(Eigen3::Eigen INTERFACE IMPORTED)
     target_include_directories(Eigen3::Eigen INTERFACE "${EIGEN_DIR}")
 else()
-    find_package(Eigen3 CONFIG)
+    find_package(Eigen3 ${Eigen3_FIND_VERSION} CONFIG)
     if(Eigen3_DIR)
         message(STATUS "Eigen3: found config at '${Eigen3_DIR}'.")
     else()
diff --git a/src/helpers/CMakeLists.txt b/src/helpers/CMakeLists.txt
index 81e8fc83ee..2450d3dade 100644
--- a/src/helpers/CMakeLists.txt
+++ b/src/helpers/CMakeLists.txt
@@ -34,7 +34,7 @@ message("Running CMakeLists.txt in /src/helpers")
 #                   (ifcopenshell.util.element)
 #   * Element     — get_predefined_type (ifcopenshell.util.element)
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 # helpers_math: the schema-free subset — unit conversion tables and Helmert
 # matrix math over plain numbers. No IfcParse, no Qt, no schema dispatch, so it
diff --git a/src/ifcgeom/CMakeLists.txt b/src/ifcgeom/CMakeLists.txt
index fc73187bcd..426e7d11ce 100644
--- a/src/ifcgeom/CMakeLists.txt
+++ b/src/ifcgeom/CMakeLists.txt
@@ -41,7 +41,7 @@ if(UNIX)
     find_package(Threads)
 endif()
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 add_subdirectory(kernels)
 set(kernel_libraries ${kernel_libraries} PARENT_SCOPE)
diff --git a/src/ifcgeom/mapping/CMakeLists.txt b/src/ifcgeom/mapping/CMakeLists.txt
index 300c1311c4..6090d6e648 100644
--- a/src/ifcgeom/mapping/CMakeLists.txt
+++ b/src/ifcgeom/mapping/CMakeLists.txt
@@ -1,4 +1,4 @@
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 set(mapping_plugin_runtime_dir "$<TARGET_FILE_DIR:IfcGeom>")
 
diff --git a/src/ifcviewer/CMakeLists.txt b/src/ifcviewer/CMakeLists.txt
index 820af7ed30..b426b26398 100644
--- a/src/ifcviewer/CMakeLists.txt
+++ b/src/ifcviewer/CMakeLists.txt
@@ -30,7 +30,7 @@ endif()
 # Eigen3 — used by Federation matrices, ViewportWindow's instance compose,
 # the per-model coordinate-operation matrices stored on ModelGpuData, and
 # everywhere a 4x4 transform shows up. Header-only, works under Emscripten.
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 # wgpu-native — fetched as a pre-built binary release from upstream.
 # Under Emscripten this whole block is skipped; the web build links
diff --git a/src/ifcviewer/tests/CMakeLists.txt b/src/ifcviewer/tests/CMakeLists.txt
index 94c1c2fb27..bf0f7cd2ff 100644
--- a/src/ifcviewer/tests/CMakeLists.txt
+++ b/src/ifcviewer/tests/CMakeLists.txt
@@ -93,7 +93,7 @@ add_ifcviewer_unit_test(test_sidecar_layout
 # InstanceCompose: matrix composition + cross-model object_id lookup.
 # Pulls in wgpu_native for the WGPUBuffer typedef via ModelGpuData.h
 # (never touched at runtime). Eigen for Matrix4d.
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 add_ifcviewer_unit_test(test_instance_compose
     SOURCES ${IFCVIEWER_SRC}/InstanceCompose.cpp
     LIBS wgpu_native Eigen3::Eigen
@@ -150,7 +150,7 @@ endif()
 # directly and enable AUTOMOC for the Q_OBJECT moc-generation.
 find_package(Qt${QT_VERSION} COMPONENTS Core Gui Test REQUIRED PATHS ${QT_DIR})
 
-find_package(Eigen3 REQUIRED)
+find_package(Eigen3 ${EIGEN_MIN_VERSION} REQUIRED)
 
 add_executable(test_federation
     test_federation.cpp