diff --git a/src/borg/__init__.py b/src/borg/__init__.py
index d46c07c50..9b38c42b9 100644
--- a/src/borg/__init__.py
+++ b/src/borg/__init__.py
@@ -8,7 +8,7 @@ __version_tuple__ = parse_version(__version__).release
 # assert that all semver components are integers
 # this is mainly to show errors when people repackage poorly
 # and setuptools_scm determines a 0.1.dev... version
-assert all(isinstance(v, int) for v in __version_tuple__), (
+assert not __version__.startswith("0.1.dev") and all(isinstance(v, int) for v in __version_tuple__), (
     """\
 Broken BorgBackup version metadata: %r
 
diff --git a/src/borg/testsuite/version_test.py b/src/borg/testsuite/version_test.py
index 4b4383332..d33fa0600 100644
--- a/src/borg/testsuite/version_test.py
+++ b/src/borg/testsuite/version_test.py
@@ -15,6 +15,8 @@ from ..version import parse_version, format_version
         ("1.0.0a1.dev204+g8866961", (1, 0, 0, -4, 1)),
         ("1.0.0+d20170606", (1, 0, 0, -1)),
         # Pre-release versions:
+        ("1.0.0.dev1", (1, 0, 0, -9, 1)),
+        ("1.0.0dev2", (1, 0, 0, -9, 2)),
         ("1.0.0a1", (1, 0, 0, -4, 1)),
         ("1.0.0a2", (1, 0, 0, -4, 2)),
         ("1.0.0b3", (1, 0, 0, -3, 3)),
@@ -39,6 +41,7 @@ def test_parse_version_invalid(invalid_version):
 @pytest.mark.parametrize(
     "version_str, version_tuple",
     [
+        ("1.0.0.dev1", (1, 0, 0, -9, 1)),
         ("1.0.0a1", (1, 0, 0, -4, 1)),
         ("1.0.0", (1, 0, 0, -1)),
         ("1.0.0a2", (1, 0, 0, -4, 2)),
diff --git a/src/borg/version.py b/src/borg/version.py
index 12eeea168..473fe5f11 100644
--- a/src/borg/version.py
+++ b/src/borg/version.py
@@ -17,7 +17,7 @@ def parse_version(version):
     """
     version_re = r"""
         (?P<major>\d+)\.(?P<minor>\d+)\.(?P<patch>\d+)   # version, e.g. 1.2.33
-        (?P<prerelease>(?P<ptype>a|b|rc)(?P<pnum>\d+))?  # optional prerelease, e.g. a1 or b2 or rc33
+        (?P<prerelease>\.?(?P<ptype>a|b|rc|dev)(?P<pnum>\d+))?  # optional prerelease, e.g. a1 or b2 or rc33 or .dev1
     """
     m = re.match(version_re, version, re.VERBOSE)
     if m is None:
@@ -25,7 +25,7 @@ def parse_version(version):
     gd = m.groupdict()
     version = [int(gd["major"]), int(gd["minor"]), int(gd["patch"])]
     if m.lastgroup == "prerelease":
-        p_type = {"a": -4, "b": -3, "rc": -2}[gd["ptype"]]
+        p_type = {"a": -4, "b": -3, "rc": -2, "dev": -9}[gd["ptype"]]
         p_num = int(gd["pnum"])
         version += [p_type, p_num]
     else:
@@ -44,6 +44,6 @@ def format_version(version):
         elif part == -1:
             break
         else:
-            f[-1] = f[-1] + {-2: "rc", -3: "b", -4: "a"}[part] + str(next(it))
+            f[-1] = f[-1] + {-2: "rc", -3: "b", -4: "a", -9: ".dev"}[part] + str(next(it))
             break
     return ".".join(f)