diff --git a/tests/integration/test_install_misc.py b/tests/integration/test_install_misc.py
index e91da827..503d409f 100644
--- a/tests/integration/test_install_misc.py
+++ b/tests/integration/test_install_misc.py
@@ -7,15 +7,15 @@ def test_install_uri_with_extras(pipenv_instance_private_pypi):
     file_uri = "http://localhost:8080/packages/plette/plette-0.2.2-py2.py3-none-any.whl"
     with pipenv_instance_private_pypi() as p:
         with open(p.pipfile_path, 'w') as f:
-            contents = """
+            contents = f"""
 [[source]]
-url = "{index}"
+url = "{p.index_url}"
 verify_ssl = false
 name = "testindex"
 
 [packages]
 plette = {{file = "{file_uri}", extras = ["validation"]}}
-""".format(file_uri=file_uri, index=p.index_url)
+"""
             f.write(contents)
         c = p.pipenv("install")
         assert c.returncode == 0
diff --git a/tests/integration/test_install_twists.py b/tests/integration/test_install_twists.py
index 04370aa3..79a97e94 100644
--- a/tests/integration/test_install_twists.py
+++ b/tests/integration/test_install_twists.py
@@ -210,13 +210,11 @@ def test_install_local_uri_special_character(pipenv_instance_private_pypi, tests
         os.makedirs(artifact_path, exist_ok=True)
         shutil.copy(source_path, os.path.join(artifact_path, file_name))
         with open(p.pipfile_path, "w") as f:
-            contents = """
+            contents = f"""
 # Pre comment
 [packages]
-six = {{path = "./artifacts/{}"}}
-            """.format(
-                file_name
-            )
+six = {{path = "./artifacts/{file_name}"}}
+            """
             f.write(contents.strip())
         c = p.pipenv("install")
         assert c.returncode == 0
diff --git a/tests/integration/test_install_uri.py b/tests/integration/test_install_uri.py
index 53ed3e18..1ef124b0 100644
--- a/tests/integration/test_install_uri.py
+++ b/tests/integration/test_install_uri.py
@@ -219,7 +219,7 @@ def test_vcs_entry_supersedes_non_vcs(pipenv_instance_pypi):
         jinja2_uri = p._pipfile.get_fixture_path("git/jinja2").as_uri()
         with open(p.pipfile_path, "w") as f:
             f.write(
-                """
+                f"""
 [[source]]
 url = "https://pypi.org/simple"
 verify_ssl = true
@@ -227,8 +227,8 @@ name = "pypi"
 
 [packages]
 Flask = "*"
-Jinja2 = {{ref = "2.11.0", git = "{}"}}
-            """.format(jinja2_uri).strip()
+Jinja2 = {{ref = "2.11.0", git = "{jinja2_uri}"}}
+            """.strip()
             )
         c = p.pipenv("install")
         assert c.returncode == 0
diff --git a/tests/integration/test_lock.py b/tests/integration/test_lock.py
index f3e21c06..1064f066 100644
--- a/tests/integration/test_lock.py
+++ b/tests/integration/test_lock.py
@@ -477,15 +477,15 @@ def test_vcs_lock_respects_top_level_pins(pipenv_instance_private_pypi):
 @pytest.mark.lock
 def test_lock_after_update_source_name(pipenv_instance_pypi):
     with pipenv_instance_pypi() as p:
-        contents = """
+        contents = f"""
 [[source]]
-url = "{}"
+url = "{p.index_url}"
 verify_ssl = true
 name = "test"
 
 [packages]
 six = "*"
-        """.format(p.index_url).strip()
+        """.strip()
         with open(p.pipfile_path, 'w') as f:
             f.write(contents)
         c = p.pipenv("lock")
@@ -644,9 +644,9 @@ requests = "*"
 @pytest.mark.lock
 def test_lock_specific_named_category(pipenv_instance_private_pypi):
     with pipenv_instance_private_pypi(pipfile=False) as p:
-        contents = """
+        contents = f"""
 [[source]]
-url = "{}"
+url = "{p.index_url}"
 verify_ssl = true
 name = "test"
 
@@ -655,7 +655,7 @@ requests = "*"
 
 [prereq]
 six = "*"
-        """.format(p.index_url).strip()
+        """.strip()
         with open(p.pipfile_path, 'w') as f:
             f.write(contents)
         c = p.pipenv("lock --categories prereq")
diff --git a/tests/integration/test_project.py b/tests/integration/test_project.py
index ce80a2a2..e9067bcc 100644
--- a/tests/integration/test_project.py
+++ b/tests/integration/test_project.py
@@ -38,9 +38,9 @@ pytz = "*"
 def test_get_source(pipenv_instance_private_pypi, lock_first):
     with pipenv_instance_private_pypi() as p:
         with open(p.pipfile_path, 'w') as f:
-            contents = """
+            contents = f"""
 [[source]]
-url = "{}"
+url = "{p.index_url}"
 verify_ssl = false
 name = "testindex"
 
@@ -54,7 +54,7 @@ pytz = "*"
 six = {{version = "*", index = "pypi"}}
 
 [dev-packages]
-            """.format(p.index_url).strip()
+            """.strip()
             f.write(contents)
 
         if lock_first:
@@ -106,10 +106,7 @@ def test_maintain_file_line_endings(pipenv_instance_pypi, newlines):
             with open(fn) as f:
                 f.read()    # Consumes the content to detect newlines.
                 actual_newlines = f.newlines
-            assert actual_newlines == newlines, '{!r} != {!r} for {}'.format(
-                actual_newlines, newlines, fn,
-            )
-            # message because of  https://github.com/pytest-dev/pytest/issues/3443
+            assert actual_newlines == newlines, f'{actual_newlines!r} != {newlines!r} for {fn}'
 
 
 @pytest.mark.project
@@ -118,9 +115,9 @@ def test_maintain_file_line_endings(pipenv_instance_pypi, newlines):
 def test_many_indexes(pipenv_instance_pypi):
     with pipenv_instance_pypi() as p:
         with open(p.pipfile_path, 'w') as f:
-            contents = """
+            contents = f"""
 [[source]]
-url = "{}"
+url = "{p.index_url}"
 verify_ssl = false
 name = "testindex"
 
@@ -139,7 +136,7 @@ pytz = "*"
 six = {{version = "*", index = "pypi"}}
 
 [dev-packages]
-            """.format(p.index_url).strip()
+            """.strip()
             f.write(contents)
         c = p.pipenv('install')
         assert c.returncode == 0