diff --git a/.travis/py2.docker b/.travis/py2.docker
deleted file mode 100644
index f5fb0cb..0000000
--- a/.travis/py2.docker
+++ /dev/null
@@ -1,63 +0,0 @@
-FROM kernsuite/base:6
-
-RUN docker-apt-install python-casacore casacore-data makems casarest \
-                       python-pip git wget meqtrees meqtrees-timba owlcat
-
-WORKDIR /src
-RUN wget https://codeload.github.com/ska-sa/pyxis/tar.gz/refs/tags/v1.7.1 && \
-    tar zxvf v1.7.1 && \
-    rm v1.7.1
-RUN pip install -e ./pyxis-1.7.1
-
-WORKDIR /code
-ADD . /code/tigger-lsm
-RUN pip install ./tigger-lsm
-
-# basic install tests
-RUN flag-ms.py --help
-RUN meqtree-pipeliner.py --help
-RUN pyxis --help
-
-# run end to end test when built
-RUN pip install nose
-WORKDIR /src/pyxis-1.7.1/Pyxis/recipes/meqtrees-batch-test
-RUN python -m "nose"
-
-#######################################
-# run oleg's new tests
-#######################################
-ENV GITHUB_WORKSPACE=/code/tigger-lsm
-# Test conversion to .txt models
-RUN tigger-convert $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.lsm.html /tmp/output.txt -f \
-    --output-format "name ra_d dec_d i q u v i q u v spi rm emaj_s emin_s pa_d freq0"
-RUN tigger-convert $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.lsm.html /tmp/output.recentred.txt -f --center 85.5deg,49.9deg --rename \
-    --output-format "name ra_d dec_d i q u v i q u v spi rm emaj_s emin_s pa_d freq0"
-RUN echo "Checking reference LSM"
-RUN diff $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.reference.txt /tmp/output.txt
-RUN echo "Checking recentred reference LSM"
-RUN diff $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.recentred.reference.txt /tmp/output.recentred.txt
-
-#Test reverse conversion to .lsm.html models
-RUN tigger-convert /tmp/output.txt /tmp/output.lsm.html -f
-
-#Test .gaul conversions
-RUN tigger-convert $GITHUB_WORKSPACE/test/deep4.gaul /tmp/deep4.lsm.html -f 
-RUN tigger-convert $GITHUB_WORKSPACE/test/deep4.gaul /tmp/deep4.txt -f --output-format "name ra_d dec_d i q u v spi rm emaj_s emin_s pa_d freq0"
-RUN diff $GITHUB_WORKSPACE/test/deep4.reference.txt /tmp/deep4.txt
-
-# Test .AIPSCC conversions
-RUN gunzip <$GITHUB_WORKSPACE/test/3C147-L-A-CLEAN.fits.gz >/tmp/3C147-L-A-CLEAN.fits
-RUN tigger-convert /tmp/3C147-L-A-CLEAN.fits /tmp/3C147-L-A-CLEAN.fits.lsm.html -f
-RUN tigger-convert /tmp/3C147-L-A-CLEAN.fits.lsm.html /tmp/3C147-L-A-CLEAN.txt -f --output-format "name ra_d dec_d i q u v"
-RUN zdiff $GITHUB_WORKSPACE/test/3C147-L-A-CLEAN.txt.gz /tmp/3C147-L-A-CLEAN.txt
-
-# Testing tigger-restore and tigger-make-brick
-RUN cp $GITHUB_WORKSPACE/test/3C147tmp.fits /tmp
-RUN tigger-make-brick $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.lsm.html /tmp/3C147tmp.fits 
-RUN tigger-restore -f $GITHUB_WORKSPACE/test/3C147tmp.fits $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.lsm.html /tmp/restored.fits
-
-#Test tigger-tag
-RUN tigger-tag $GITHUB_WORKSPACE/test/3C147-HI6.refmodel.lsm.html 'r<0.5d' inner=1 -o /tmp/tmp.lsm.html -f
-
-ENTRYPOINT ["meqtree-pipeliner.py"]
-CMD ["--help"]
diff --git a/Jenkinsfile.sh b/Jenkinsfile.sh
index a1a35ba..06555f6 100644
--- a/Jenkinsfile.sh
+++ b/Jenkinsfile.sh
@@ -21,5 +21,4 @@ cd $PROJECTS_DIR/meqtrees-tigger-lsm
 IMAGENAME="mttiglsmpr"
 
 # build and test
-docker build -f .travis/py2.docker -t "${IMAGENAME}27:$BUILD_NUMBER" --no-cache=true .
 docker build -f .travis/py3.docker -t "${IMAGENAME}36:$BUILD_NUMBER" --no-cache=true .
diff --git a/Tigger/Coordinates.py b/Tigger/Coordinates.py
index 6f35dc1..a75dcc4 100644
--- a/Tigger/Coordinates.py
+++ b/Tigger/Coordinates.py
@@ -24,6 +24,8 @@
 # 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 #
 from __future__ import print_function, division, absolute_import
+
+from astropy.wcs.wcs import InvalidTransformError
 import Tigger
 from Tigger import startup_dprint
 
@@ -348,12 +350,28 @@ def __init__(self, header):
             # pix2world then fails expecting N x 4. Using astropy wcs methods and not sub-classing FITSWCSpix
             # avoids the error and a reliance on naxis.
 
-            # get astropy WCS
-            self.wcs = WCS(header)
-
             # get number of axis
             naxis = header['NAXIS']
 
+            # get astropy WCS
+            try:
+                self.wcs = WCS(header)
+            except InvalidTransformError as e:
+                if 'CUNIT' in str(e):
+                    # check header for incorrect CUNIT entry 'M/S'
+                    for iaxis in range(naxis):
+                        name = header.get("CUNIT%d" % (iaxis + 1), '').upper()
+                        if name.startswith("M/S"):
+                            # correct the header
+                            header.set("CUNIT%d" % (iaxis + 1), 'm/s')
+                    # re-load WCS
+                    try:
+                        self.wcs = WCS(header)
+                    except InvalidTransformError as e:
+                        raise RuntimeError(f"Error WCS header {e}")
+                else:
+                    raise RuntimeError(f"Error WCS header {e}")
+
             # get ra and dec axis
             self.ra_axis = self.dec_axis = None
             for iaxis in range(naxis):
diff --git a/setup.py b/setup.py
index cbfe6df..d6764b9 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,7 @@
     extras_require=extras_require,
     scripts=scripts,
     package_data=package_data,
-    python_requires='>=2.7.0',
+    python_requires='>=3.6',
     description="Python libraries and command-line tools for manipulating Tigger-format LSMs",
     author="Oleg Smirnov",
     author_email="osmirnov@gmail.com",