diff --git a/.dockerignore b/.dockerignore
index 766836180..d0508a2da 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -1,2 +1,4 @@
 **/__pycache__
 **/*.pyc
+data
+venv
diff --git a/.travis.yml b/.travis.yml
index b435a1c98..0ecdc6819 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
-dist: xenial
+dist: bionic
 language: python
 python:
-- '3.5'
 - '3.6'
 - '3.7'
 - '3.8'
@@ -21,28 +20,22 @@ cache: pip
 before_install:
 - export BOTO_CONFIG=/dev/null
 install:
-- pip install --upgrade pip
-- pip install pipenv
-- pip install --upgrade pytest
-- pipenv install --dev --skip-lock
+- pip install .[dev]
 - travis_wait 30 python -m nltk.downloader punkt
+# Selectively install the optional dependencies for some Python versions
 # Install the optional neural network dependencies (TensorFlow and LMDB)
-# - except for one Python version (3.8) so that we can test also without them
-# (tensorflow 2.0.0 isn't available for python 3.8 anyway)
-- if [[ $TRAVIS_PYTHON_VERSION != '3.8' ]]; then pip install .[nn]; fi
+# - except for one Python version (3.7) so that we can test also without them
+- if [[ $TRAVIS_PYTHON_VERSION != '3.7' ]]; then pip install .[nn]; fi
 # Install the optional Omikuji dependency
-# - except for one Python version (3.6) so that we can test also without them
-- if [[ $TRAVIS_PYTHON_VERSION != '3.6' ]]; then pip install .[omikuji]; fi
-# For Python 3.5, also install optional dependencies that were not specified in Pipfile
-# For other Python versions we will only run the tests that depend on pure Python modules
+# - except for one Python version (3.7) so that we can test also without them
+- if [[ $TRAVIS_PYTHON_VERSION != '3.7' ]]; then pip install .[omikuji]; fi
+# For Python 3.6, install the optional dependencies that depend on system libraries
 # - fastText dependencies
-- if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install fasttextmirror==0.8.22; fi
+- if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then pip install .[fasttext]; fi
 # - voikko dependencies
-- if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install voikko; fi
+- if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then pip install .[voikko]; fi
 # - vw dependencies
-- if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then sudo ln -sf /usr/lib/x86_64-linux-gnu/libboost_python-py35.a /usr/lib/x86_64-linux-gnu/libboost_python3.a; fi
-- if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then sudo ln -sf /usr/lib/x86_64-linux-gnu/libboost_python-py35.so /usr/lib/x86_64-linux-gnu/libboost_python3.so; fi
-- if [[ $TRAVIS_PYTHON_VERSION == '3.5' ]]; then pip install vowpalwabbit==8.7.*; fi
+- if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then pip install .[vw]; fi
 script:
 - pytest --cov=./
 after_success:
diff --git a/Dockerfile b/Dockerfile
index c1eed5cd5..73be0b507 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,7 +14,6 @@ RUN apt-get update \
 	&& apt-get install -y --no-install-recommends \
 		build-essential \
 	&& pip install --no-cache-dir \
-		cython \
 		fasttextmirror==0.8.22 \
 	## Vowpal Wabbit
 	&& apt-get install -y --no-install-recommends \
@@ -54,7 +53,7 @@ RUN apt-get update \
 	&& pip install --no-cache-dir \
 		voikko \
 		vowpalwabbit==8.7.* \
-		tensorflow==2.0.* \
+		tensorflow==2.2.0 \
 		omikuji==0.2.* \
 	# For Docker healthcheck:
 	&& apt-get install -y --no-install-recommends curl \
@@ -63,26 +62,21 @@ RUN apt-get update \
 	&& rm -rf /root/.cache/pip*/*
 
 
-## Install Annif:
-# Files needed by pipenv install:
-COPY Pipfile README.md setup.py /Annif/
-WORKDIR /Annif
+## Install Annif (including development packages and making the installation editable):
 
-# Handle occasional timeout in nltk.downloader with 3 tries
-RUN pip install pipenv --no-cache-dir \
-	&& pipenv install --dev --system --skip-lock \
-	&& for i in 1 2 3; do python -m nltk.downloader punkt -d /usr/share/nltk_data && break || sleep 1; done \
-	&& pip uninstall -y pipenv \
-	&& rm -rf /root/.cache/pip*/*
+COPY setup.py README.md LICENSE.txt projects.cfg.dist /Annif/
+COPY annif /Annif/annif
+COPY tests /Annif/tests
+WORKDIR /Annif
 
+RUN pip install .[dev] --no-cache-dir \
+	&& pip install -e . \
+	# Download nltk data (handle occasional timeout in with 3 tries)
+	&& for i in 1 2 3; do python -m nltk.downloader punkt -d /usr/share/nltk_data && break || sleep 1; done
 
-COPY annif annif
-COPY projects.cfg.dist projects.cfg.dist
-COPY LICENSE.txt LICENSE.txt
 
 WORKDIR /annif-projects
 
-
 # Switch user to non-root:
 RUN groupadd -g 998 annif_user \
     && useradd -r -u 998 -g annif_user annif_user \
diff --git a/Pipfile b/Pipfile
deleted file mode 100644
index bf2ef9502..000000000
--- a/Pipfile
+++ /dev/null
@@ -1,31 +0,0 @@
-[[source]]
-url = "https://pypi.python.org/simple"
-name = "pypi"
-verify_ssl = true
-
-[dev-packages]
-codecov = "*"
-pytest-cov = "*"
-pytest-watch = "*"
-pytest-flask = "*"
-"pytest-pep8" = "*"
-swagger-tester = "*"
-bumpversion = "*"
-responses = "*"
-
-[packages]
-"e1839a8" = {path = ".", editable = true}
-connexion = {extras = ["swagger-ui"]}
-swagger-ui-bundle = "*"
-flask-cors = "*"
-click = "==7.1.*"
-click-log = "*"
-joblib = "==0.14.*"
-nltk = "*"
-gensim = "==3.8.*"
-scikit-learn = "==0.22.*"
-rdflib = "*"
-gunicorn = "!=20.0.0"
-numpy = "==1.17.*"
-
-[requires]
diff --git a/README.md b/README.md
index 02eae8d4f..0541c05cf 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ already functional for many common tasks.
 
 # Basic install
 
-You will need Python 3.5+ to install Annif.
+You will need Python 3.6+ to install Annif.
 
 The recommended way is to install Annif from
 [PyPI](https://pypi.org/project/annif/) into a virtual environment.
@@ -52,25 +52,22 @@ for details.
 
 A development version of Annif can be installed by cloning the [GitHub
 repository](https://github.com/NatLibFi/Annif).
-[Pipenv](https://docs.pipenv.org/) is used for managing dependencies for the
-development version.
 
 ## Installation and setup
 
 Clone the repository.
 
 Switch into the repository directory.
-Install pipenv if you don't have it:
 
-    pip install pipenv  # or pip3 install pipenv
+Create and activate a virtual environment (optional, but highly recommended):
 
-Install dependencies and download NLTK data:
+    python3 -m venv venv
+    . venv/bin/activate
 
-    pipenv install  # use --dev if you want to run tests etc.
+Install dependencies (including development) and make the installation editable:
 
-Enter the virtual environment:
-
-    pipenv shell
+    pip install .[dev]
+    pip install -e .
 
 You will also need NLTK data files:
 
@@ -82,7 +79,7 @@ Start up the application:
 
 ## Unit tests
 
-Run `pipenv shell` to enter the virtual environment and then run `pytest`.
+Run `. venv/bin/activate` to enter the virtual environment and then run `pytest`.
 To have the test suite watch for changes in code and run automatically, use
 pytest-watch by running `ptw`.
 
diff --git a/setup.py b/setup.py
index ad7c435dc..499050eda 100644
--- a/setup.py
+++ b/setup.py
@@ -30,6 +30,7 @@ def read(fname):
         'gensim==3.8.*',
         'scikit-learn==0.22.*',
         'rdflib',
+        'gunicorn',
         'numpy==1.17.*',
     ],
     tests_require=['py', 'pytest', 'requests'],
@@ -37,8 +38,19 @@ def read(fname):
         'fasttext': ['fasttextmirror==0.8.22'],
         'voikko': ['voikko'],
         'vw': ['vowpalwabbit==8.7.*'],
-        'nn': ['tensorflow==2.0.*', 'lmdb==0.98'],
+        'nn': ['tensorflow==2.2.0', 'lmdb==0.98'],
         'omikuji': ['omikuji==0.2.*'],
+        'dev': [
+          'codecov',
+          'pytest-cov',
+          'pytest-watch',
+          'pytest-flask',
+          'pytest-pep8',
+          'swagger-tester',
+          'bumpversion',
+          'responses',
+          'autopep8'
+        ]
     },
     entry_points={
         'console_scripts': ['annif=annif.cli:cli']},