diff --git a/.travis.yml b/.travis.yml
index 18debc2..b1a6f4a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -63,6 +63,7 @@ addons:
     packages:
       - ibverbs-utils
       - libibverbs-dev
+      - realpath
       - wget
       - zsh
 
diff --git a/mpienv/mpienv_init.py b/mpienv/mpienv_init.py
index d4c2133..5a775f4 100644
--- a/mpienv/mpienv_init.py
+++ b/mpienv/mpienv_init.py
@@ -12,11 +12,11 @@
 
 mkdir -p ${MPIENV_VERSIONS_DIR}
 
-function usage() {
+usage() {
     echo "Usage: mpienv [command] [options...]"
 }
 
-function mpienv() {
+mpienv() {
     if [ "0" = "${#*}" ]; then
         usage
         return -1
diff --git a/mpienv/py.py b/mpienv/py.py
index 92e9a1c..3ea38f0 100644
--- a/mpienv/py.py
+++ b/mpienv/py.py
@@ -2,10 +2,11 @@
 
 from __future__ import print_function
 import errno
-import glob
 import os
 import os.path
 import shutil
+from subprocess import PIPE
+from subprocess import Popen
 import sys
 
 import mpienv.pip as pip
@@ -35,8 +36,11 @@ def __init__(self, libname, conf, name):
             mkdir_p(self._pylib_dir)
 
     def is_installed(self):
-        libs = glob.glob(os.path.join(self._pylib_dir, self._libname, '*.so'))
-        return len(libs) > 0
+        """Check if mpi4py is installed"""
+        python = sys.executable
+        p = Popen([python, '-c', 'import mpi4py'], stdout=PIPE, stderr=PIPE)
+        p.communicate()
+        return p.returncode == 0
 
     def install(self, env):
         sys.stderr.write(
diff --git a/tests/test_main.sh b/tests/test_main.sh
index 412cfdf..9bc45b1 100755
--- a/tests/test_main.sh
+++ b/tests/test_main.sh
@@ -410,10 +410,10 @@ test_reg_issue10() {
     # https://github.com/keisukefukuda/mpienv/issues/10
     assertSuccess mpienv autodiscover -q --add ${MPI_PREFIX}
 
-    mpienv use --mpi4py ${MPICH} # this command should install mpi4py to mpich-3.2
+    mpienv use ${MPICH} # this command should install mpi4py to mpich-3.2
     mpienv rename ${MPICH} mpix # The mpi4py module should be taken over to 'mpix'
 
-    OUT=$(mpienv use mpix 2>&1) # this command should NOT intall mpi4py again
+    OUT=$(mpienv use mpix 2>&1) # this command should NOT install mpi4py again
 
     # If the `use` command does not run `pip install mpi4py`,
     # which is a correct behavior, E-S should be < 1 [s].
@@ -434,7 +434,10 @@ test_reg_issue_timeout() {
 test_reg_issue_134_add_relpath() {
     # Regression test for
     pushd $HOME
-    OMPI_relpath=$(realpath --relative-to=$PWD $OMPI_ROOT)
+    echo realpath --version
+    realpath --version
+    # OMPI_relpath=$(realpath --relative-to $PWD $OMPI_ROOT)
+    OMPI_relpath=$(python -c "import os.path; print(os.path.relpath('${OMPI_ROOT}', '${PWD}'))")
     mpienv add ${OMPI_relpath}
     mpienv use ${OMPI}
     popd