@@ -471,7 +471,7 @@ def next_version(self, part: str, prerelease_token: str = "rc") -> "Version":
                 f"Invalid part. Expected one of {validparts}, but got {part!r}"
             )
         version = self
-        if (version.prerelease or version.build) and (
+        if version.prerelease and (
             part == "patch"
             or (part == "minor" and version.patch == 0)
             or (part == "major" and version.minor == version.patch == 0)
 
@@ -198,6 +198,16 @@ def test_next_version_with_invalid_parts():
         ("0.2.0-rc.1", "patch", "0.2.0"),  # same as "minor"
         ("1.0.0-rc.1", "patch", "1.0.0"),  # same as "major"
         ("1.0.0-rc.1", "minor", "1.0.0"),  # same as "major"
+        # build-only versions: build metadata does not affect precedence,
+        # so next_version should bump the version, not just strip the build
+        ("1.2.3+build.5", "patch", "1.2.4"),
+        ("1.0.0+build.5", "patch", "1.0.1"),
+        ("0.1.4+build.5", "patch", "0.1.5"),
+        ("1.2.0+build.5", "minor", "1.3.0"),
+        ("1.0.0+build.5", "major", "2.0.0"),
+        # prerelease+build: build is stripped along with prerelease during finalization
+        ("1.2.3-rc.1+build.5", "patch", "1.2.3"),
+        ("1.2.3-rc.1+build.5", "prerelease", "1.2.3-rc.2"),
     ],
 )
 def test_next_version_with_versioninfo(version, part, expected):
Original file line number	Diff line number	Diff line change
`@@ -471,7 +471,7 @@ def next_version(self, part: str, prerelease_token: str = "rc") -> "Version":`
`471`	`471`	`f"Invalid part. Expected one of {validparts}, but got {part!r}"`
`472`	`472`	`)`
`473`	`473`	`version = self`
`474`		`- if (version.prerelease or version.build) and (`
	`474`	`+ if version.prerelease and (`
`475`	`475`	`part == "patch"`
`476`	`476`	`or (part == "minor" and version.patch == 0)`
`477`	`477`	`or (part == "major" and version.minor == version.patch == 0)`