diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6e0d82..b288747 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -169,6 +169,26 @@ if(Geant4_FOUND)
     add_compile_definitions(HAVE_GEANT4)
     set(HAVE_GEANT4 1)
 
+    # Workaround: Geant4's G4EXPATShim creates EXPAT::EXPAT (uppercase) with
+    # IMPORTED_LOCATION "${EXPAT_LIBRARY}", but EXPAT_LIBRARY is empty when using
+    # conda's config-mode expat package (which installs as expat::expat lowercase).
+    # Resolve the actual library path from expat::expat or via find_library.
+    if(TARGET EXPAT::EXPAT)
+        get_target_property(_expat_loc EXPAT::EXPAT IMPORTED_LOCATION)
+        if(NOT _expat_loc OR _expat_loc MATCHES "NOTFOUND|^$")
+            if(TARGET expat::expat)
+                get_target_property(_expat_loc expat::expat IMPORTED_LOCATION_NOCONFIG)
+            endif()
+            if(NOT _expat_loc OR _expat_loc MATCHES "NOTFOUND|^$")
+                find_library(_expat_loc NAMES expat)
+            endif()
+            if(_expat_loc)
+                set_target_properties(EXPAT::EXPAT PROPERTIES IMPORTED_LOCATION "${_expat_loc}")
+            endif()
+        endif()
+        unset(_expat_loc)
+    endif()
+
     # Sanitize Geant4 targets to remove Qt5 dependencies that conflict with VTK/Qt6
     if(TARGET Geant4::G4interfaces)
         set_target_properties(Geant4::G4interfaces PROPERTIES