diff --git a/src/ifcpatch/ifcpatch/recipes/MergeProject.py b/src/ifcpatch/ifcpatch/recipes/MergeProject.py
index a65cbeeaac..412a45b256 100644
--- a/src/ifcpatch/ifcpatch/recipes/MergeProject.py
+++ b/src/ifcpatch/ifcpatch/recipes/MergeProject.py
@@ -16,9 +16,12 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with IfcPatch.  If not, see <http://www.gnu.org/licenses/>.
 
+import numpy as np
 import ifcopenshell
-import ifcopenshell.util.element
 import ifcopenshell.util.unit
+import ifcopenshell.util.element
+import ifcopenshell.util.geolocation
+from ifcpatch.recipes.SetFalseOrigin import Patcher as SetFalseOrigin
 from typing import Union
 from logging import Logger
 
@@ -51,12 +54,25 @@ class Patcher:
 
     def patch(self):
         if isinstance(self.filepath, ifcopenshell.file):
-            source = self.filepath
+            other = self.filepath
         else:
-            source = ifcopenshell.open(self.filepath)
+            other = ifcopenshell.open(self.filepath)
 
-        if (main_unit := self.get_unit_name(self.file)) != self.get_unit_name(source):
-            source = ifcopenshell.util.unit.convert_file_length_units(source, main_unit)
+        if (main_unit := self.get_unit_name(self.file)) != self.get_unit_name(other):
+            other = ifcopenshell.util.unit.convert_file_length_units(other, main_unit)
+
+        existing_enh = np.array(
+            ifcopenshell.util.geolocation.auto_xyz2enh(self.file, 0, 0, 0, should_return_in_map_units=False)
+        )
+        other_enh = np.array(
+            ifcopenshell.util.geolocation.auto_xyz2enh(other, 0, 0, 0, should_return_in_map_units=False)
+        )
+
+        if not np.allclose(existing_enh, other_enh):
+            x, y, z = ifcopenshell.util.geolocation.auto_enh2xyz(other, *existing_enh, is_specified_in_map_units=False)
+            e, n, h = existing_enh
+            # For now don't handle rotation because my brain is going to explode
+            SetFalseOrigin("", other, self.logger, name="", x=x, y=y, z=z, e=e, n=n, h=h).patch()
 
         self.existing_contexts: list[ifcopenshell.entity_instance] = self.file.by_type(
             "IfcGeometricRepresentationContext"
@@ -64,13 +80,13 @@ class Patcher:
         self.added_contexts: set[ifcopenshell.entity_instance] = set()
 
         original_project = self.file.by_type("IfcProject")[0]
-        merged_project = self.file.add(source.by_type("IfcProject")[0])
+        merged_project = self.file.add(other.by_type("IfcProject")[0])
 
-        for element in source.by_type("IfcGeometricRepresentationContext"):
+        for element in other.by_type("IfcGeometricRepresentationContext"):
             new = self.file.add(element)
             self.added_contexts.add(new)
 
-        for element in source:
+        for element in other:
             self.file.add(element)
 
         for inverse in self.file.get_inverse(merged_project):
diff --git a/src/ifcpatch/test/test_MergeProject.py b/src/ifcpatch/test/test_MergeProject.py
index 685f4326a5..6be9305e82 100644
--- a/src/ifcpatch/test/test_MergeProject.py
+++ b/src/ifcpatch/test/test_MergeProject.py
@@ -18,7 +18,7 @@
 
 import ifcpatch
 import ifcopenshell
-import ifcopenshell.api
+import ifcopenshell.api.georeference
 import ifcopenshell.util.placement
 import test.bootstrap
 import tempfile
@@ -81,5 +81,48 @@ class TestMergeProject(test.bootstrap.IFC4):
         assert len(output.by_type("IfcProjectedCRS")) == 1
         assert len(output.by_type("IfcMapConversion")) == 1
 
+    def test_shifting_the_source_project_to_match_the_original_project_origin(self):
+        self.file = self.setup_project(self.file)
+        second_file = self.setup_project()
+        ifcopenshell.api.georeference.add_georeferencing(self.file)
+        ifcopenshell.api.georeference.edit_georeferencing(
+            self.file, coordinate_operation={"Eastings": 10, "Northings": 20}, projected_crs={"Name": "EPSG:1234"}
+        )
+        ifcopenshell.api.georeference.add_georeferencing(second_file)
+        ifcopenshell.api.georeference.edit_georeferencing(
+            second_file, coordinate_operation={"Eastings": 30000, "Northings": 40000}, projected_crs={"Name": "EPSG:0"}
+        )
+
+        # Original file is in meters
+        wall1 = self.file.by_type("IfcWall")[0]
+        m1 = ifcopenshell.util.placement.get_local_placement(wall1.ObjectPlacement)
+        assert np.allclose(m1[:, 3], (1, 2, 3, 1))
+        global_m1 = ifcopenshell.util.geolocation.auto_local2global(self.file, m1, should_return_in_map_units=False)
+        assert np.allclose(global_m1[:, 3], (11, 22, 3, 1))
+
+        # Second file is in millimeters with a different false origin
+        wall1 = second_file.by_type("IfcWall")[0]
+        m1 = ifcopenshell.util.placement.get_local_placement(wall1.ObjectPlacement)
+        assert np.allclose(m1[:, 3], (1000, 2000, 3000, 1))
+        global_m1 = ifcopenshell.util.geolocation.auto_local2global(second_file, m1, should_return_in_map_units=False)
+        assert np.allclose(global_m1[:, 3], (31000, 42000, 3000, 1))
+
+        output = ifcpatch.execute({"file": self.file, "recipe": "MergeProject", "arguments": [second_file]})
+
+        # In the future we may use proj to support reprojection from different CRSes. For now... nope!
+        if self.file.schema != "IFC2X3":
+            assert output.by_type("IfcProjectedCRS")[0].Name == "EPSG:1234"
+
+        # The results should be in meters with the false origin of the original file
+        params = ifcopenshell.util.geolocation.get_helmert_transformation_parameters(output)
+        assert params.e == 10
+        assert params.n == 20
+        wall1, wall2 = output.by_type("IfcWall")
+        m1 = ifcopenshell.util.placement.get_local_placement(wall1.ObjectPlacement)
+        m2 = ifcopenshell.util.placement.get_local_placement(wall2.ObjectPlacement)
+        assert np.allclose(m1[:, 3], (1, 2, 3, 1))
+        assert np.allclose(m2[:, 3], (21, 22, 3, 1))
+
+
 class TestMergeProjectIFC2X3(test.bootstrap.IFC2X3, TestMergeProject):
     pass