diff --git a/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/ValidateOptions.kt b/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/ValidateOptions.kt
index 4de6a103..9fead49d 100644
--- a/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/ValidateOptions.kt
+++ b/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/ValidateOptions.kt
@@ -2,7 +2,6 @@ package com.osacky.flank.gradle.validation
 
 import com.osacky.flank.gradle.FladleConfig
 import com.osacky.flank.gradle.FlankGradleExtension.Companion.FLANK_VERSION
-import org.gradle.util.VersionNumber
 import kotlin.reflect.full.memberProperties
 
 fun validateOptionsUsed(
diff --git a/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/VersionNumber.kt b/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/VersionNumber.kt
new file mode 100644
index 00000000..d17b4b3e
--- /dev/null
+++ b/fladle-plugin/src/main/java/com/osacky/flank/gradle/validation/VersionNumber.kt
@@ -0,0 +1,196 @@
+package com.osacky.flank.gradle.validation
+
+/*
+* Copyright 2012 the original author or authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+/**
+ * Copied and trimmed from [org.gradle.util.VersionNumber].
+ */
+class VersionNumber private constructor(
+  private val major: Int,
+  private val minor: Int,
+  private val micro: Int,
+  private val patch: Int,
+  private val qualifier: String?,
+  private val scheme: AbstractScheme,
+) : Comparable<VersionNumber> {
+  override fun compareTo(other: VersionNumber): Int {
+    if (major != other.major) {
+      return major - other.major
+    }
+    if (minor != other.minor) {
+      return minor - other.minor
+    }
+    if (micro != other.micro) {
+      return micro - other.micro
+    }
+    if (patch != other.patch) {
+      return patch - other.patch
+    }
+    return qualifier.orEmpty().lowercase()
+      .compareTo(other.qualifier.orEmpty().lowercase())
+  }
+
+  override fun equals(other: Any?): Boolean {
+    return other is VersionNumber && compareTo(other) == 0
+  }
+
+  override fun hashCode(): Int {
+    var result = major
+    result = 31 * result + minor
+    result = 31 * result + micro
+    result = 31 * result + patch
+    result = 31 * result + qualifier.hashCode()
+    return result
+  }
+
+  override fun toString(): String {
+    return scheme.format(this)
+  }
+
+  /**
+   * Returns the version number scheme.
+   */
+  interface Scheme {
+    fun parse(versionString: String): VersionNumber
+
+    fun format(versionNumber: VersionNumber): String
+  }
+
+  private abstract class AbstractScheme protected constructor(val depth: Int) : Scheme {
+    override fun parse(versionString: String): VersionNumber {
+      if (versionString.isEmpty()) {
+        return UNKNOWN
+      }
+      val scanner = Scanner(versionString)
+
+      if (!scanner.hasDigit()) {
+        return UNKNOWN
+      }
+      var minor = 0
+      var micro = 0
+      var patch = 0
+      val major = scanner.scanDigit()
+      if (scanner.isSeparatorAndDigit('.')) {
+        scanner.skipSeparator()
+        minor = scanner.scanDigit()
+        if (scanner.isSeparatorAndDigit('.')) {
+          scanner.skipSeparator()
+          micro = scanner.scanDigit()
+          if (depth > 3 && scanner.isSeparatorAndDigit('.', '_')) {
+            scanner.skipSeparator()
+            patch = scanner.scanDigit()
+          }
+        }
+      }
+
+      if (scanner.isEnd) {
+        return VersionNumber(major, minor, micro, patch, null, this)
+      }
+
+      if (scanner.isQualifier) {
+        scanner.skipSeparator()
+        return VersionNumber(major, minor, micro, patch, scanner.remainder(), this)
+      }
+
+      return UNKNOWN
+    }
+
+    private class Scanner(val str: String) {
+      var pos: Int = 0
+
+      fun hasDigit(): Boolean {
+        return pos < str.length && Character.isDigit(str.get(pos))
+      }
+
+      fun isSeparatorAndDigit(vararg separators: Char): Boolean {
+        return pos < str.length - 1 && oneOf(*separators) && Character.isDigit(str.get(pos + 1))
+      }
+
+      fun oneOf(vararg separators: Char): Boolean {
+        val current = str.get(pos)
+        for (separator in separators) {
+          if (current == separator) {
+            return true
+          }
+        }
+        return false
+      }
+
+      val isQualifier: Boolean
+        get() = pos < str.length - 1 && oneOf('.', '-')
+
+      fun scanDigit(): Int {
+        val start = pos
+        while (hasDigit()) {
+          pos++
+        }
+        return str.substring(start, pos).toInt()
+      }
+
+      val isEnd: Boolean
+        get() = pos == str.length
+
+      fun skipSeparator() {
+        pos++
+      }
+
+      fun remainder(): String? {
+        return if (pos == str.length) null else str.substring(pos)
+      }
+    }
+  }
+
+  private class DefaultScheme : AbstractScheme(3) {
+    override fun format(versionNumber: VersionNumber): String {
+      return String.format(
+        VERSION_TEMPLATE,
+        versionNumber.major,
+        versionNumber.minor,
+        versionNumber.micro,
+        if (versionNumber.qualifier == null) "" else "-" + versionNumber.qualifier,
+      )
+    }
+
+    companion object {
+      private const val VERSION_TEMPLATE = "%d.%d.%d%s"
+    }
+  }
+
+  companion object {
+    private val DEFAULT_SCHEME = DefaultScheme()
+    val UNKNOWN: VersionNumber = version(0)
+
+    @JvmOverloads
+    fun version(
+      major: Int,
+      minor: Int = 0,
+    ): VersionNumber {
+      return VersionNumber(
+        major = major,
+        minor = minor,
+        micro = 0,
+        patch = 0,
+        qualifier = null,
+        scheme = DEFAULT_SCHEME,
+      )
+    }
+
+    fun parse(versionString: String): VersionNumber {
+      return DEFAULT_SCHEME.parse(versionString)
+    }
+  }
+}