diff --git a/coreplugins/contours/api.py b/coreplugins/contours/api.py
index 2c4a0d1e..603bc217 100644
--- a/coreplugins/contours/api.py
+++ b/coreplugins/contours/api.py
@@ -14,6 +14,7 @@ def calc_contours(dem, epsg, interval, output_format, simplify):
     import subprocess
     import tempfile
     import shutil
+    import glob
     from webodm import settings
 
     ext = ""
@@ -61,6 +62,17 @@ def calc_contours(dem, epsg, interval, output_format, simplify):
     
     if not os.path.isfile(outfile):
         return {'error': f'Cannot find output file: {outfile}'}
+    
+    if output_format == "ESRI Shapefile":
+        ext="zip"
+        shp_dir = os.path.join(tmpdir, "contours")
+        os.makedirs(shp_dir)
+        contour_files = glob.glob(os.path.join(tmpdir, "output.*"))
+        for cf in contour_files:
+            shutil.move(cf, shp_dir)
+
+        shutil.make_archive(os.path.join(tmpdir, 'output'), 'zip', shp_dir)
+        outfile = os.path.join(tmpdir, f"output.{ext}")
 
     return {'file': outfile}
 
diff --git a/coreplugins/contours/calc_contours.py b/coreplugins/contours/calc_contours.py
deleted file mode 100755
index 987ab5bb..00000000
--- a/coreplugins/contours/calc_contours.py
+++ /dev/null
@@ -1,93 +0,0 @@
-#%module
-#% description: Calculate contours
-#%end
-#%option
-#% key: dem_file
-#% type: string
-#% required: yes
-#% multiple: no
-#% description: GeoTIFF DEM containing the surface to calculate contours
-#%end
-#%option
-#% key: interval
-#% type: double
-#% required: yes
-#% multiple: no
-#% description: Contours interval
-#%end
-#%option
-#% key: format
-#% type: string
-#% required: yes
-#% multiple: no
-#% description: OGR output format
-#%end
-#%option
-#% key: simplify
-#% type: double
-#% required: yes
-#% multiple: no
-#% description: OGR output format
-#%end
-#%option
-#% key: epsg
-#% type: string
-#% required: yes
-#% multiple: no
-#% description: target EPSG code
-#%end
-
-# output: If successful, prints the full path to the contours file. Otherwise it prints "error"
-
-import sys
-import glob
-import os
-import shutil
-from grass.pygrass.modules import Module
-import grass.script as grass
-import subprocess
-
-def main():
-    ext = ""
-    if opts['format'] == "GeoJSON":
-        ext = "json"
-    elif opts['format'] == "GPKG":
-        ext = "gpkg"
-    elif opts['format'] == "DXF":
-        ext = "dxf"
-    elif opts['format'] == "ESRI Shapefile":
-        ext = "shp"
-
-    MIN_CONTOUR_LENGTH = 5
-    Module("r.external", input=opts['dem_file'], output="dem", overwrite=True)
-    Module("g.region", raster="dem")
-    Module("r.contour", input="dem", output="contours", step=opts["interval"], overwrite=True)
-    Module("v.generalize", input="contours", output="contours_smooth", method="douglas", threshold=opts["simplify"], overwrite=True)
-    Module("v.generalize", input="contours_smooth", output="contours_simplified", method="chaiken", threshold=1, overwrite=True)
-    Module("v.generalize", input="contours_simplified", output="contours_final", method="douglas", threshold=opts["simplify"], overwrite=True)
-    Module("v.edit", map="contours_final", tool="delete", threshold=[-1,0,-MIN_CONTOUR_LENGTH], query="length")
-    Module("v.out.ogr", input="contours_final", output="temp.gpkg", format="GPKG")
-
-    subprocess.check_call(["ogr2ogr", "-t_srs", "EPSG:%s" % opts['epsg'],
-                     '-overwrite', '-f', opts["format"], "output.%s" % ext, "temp.gpkg"], stdout=subprocess.DEVNULL)
-
-    if os.path.isfile("output.%s" % ext):
-        if opts["format"] == "ESRI Shapefile":
-            ext="zip"
-            os.makedirs("contours")
-            contour_files = glob.glob("output.*")
-            for cf in contour_files:
-                shutil.move(cf, os.path.join("contours", os.path.basename(cf)))
-
-            shutil.make_archive('output', 'zip', 'contours/')
-
-        print(os.path.join(os.getcwd(), "output.%s" % ext))
-    else:
-        print("error")
-
-    return 0
-
-if __name__ == "__main__":
-    opts, _ = grass.parser()
-    sys.exit(main())
-