diff --git a/build.gradle b/build.gradle
index 11747b70c332..7de2fb290c73 100644
--- a/build.gradle
+++ b/build.gradle
@@ -81,18 +81,6 @@ ext {
 
   minJavaVersion = JavaVersion.VERSION_11
 
-  // Declare script dependency versions outside of palantir's
-  // version unification control. These are not our main dependencies.
-  scriptDepVersions = [
-      "apache-rat": "0.11",
-      "commons-codec": "1.13",
-      "ecj": "3.25.0",
-      "javacc": "7.0.4",
-      "jflex": "1.7.0",
-      "jgit": "5.9.0.202009080501-r",
-      "flexmark": "0.61.24",
-  ]
-
   // Allow definiting external tool locations using system props.
   externalTool = { name ->
     def resolved = propertyOrDefault("${name}.exe", name as String)
@@ -101,6 +89,8 @@ ext {
   }
 }
 
+apply from: file('buildSrc/scriptDepVersions.gradle')
+
 // Include smaller chunks configuring dedicated build areas.
 // Some of these intersect or add additional functionality.
 // The order of inclusion of these files shouldn't matter (but may
@@ -152,6 +142,7 @@ apply from: file('gradle/generation/kuromoji.gradle')
 apply from: file('gradle/generation/nori.gradle')
 apply from: file('gradle/generation/icu.gradle')
 apply from: file('gradle/generation/javacc.gradle')
+apply from: file('gradle/generation/unicode-data.gradle')
 
 apply from: file('gradle/datasets/external-datasets.gradle')
 
diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index e1d90c412b1b..5d5798142dd0 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -15,26 +15,21 @@
  * limitations under the License.
  */
 
-
-// Make sure the build environment is consistent.
-apply from: file('../gradle/validation/check-environment.gradle')
-
 repositories {
   mavenCentral()
 }
 
-ext {
-  // Declare script dependency versions outside of palantir's
-  // version unification control. These are not our main dependencies.
-  scriptDepVersions = [
-      "commons-codec": "1.13"
-  ]
-}
+// Make sure the build environment is consistent.
+apply from: file('../gradle/validation/check-environment.gradle')
+
+// Load common buildSrc and script deps.
+apply from: file("scriptDepVersions.gradle")
 
 dependencies {
   implementation gradleApi()
   implementation localGroovy()
 
   implementation "commons-codec:commons-codec:${scriptDepVersions['commons-codec']}"
+  implementation "com.ibm.icu:icu4j:${scriptDepVersions['icu']}"
 }
 
diff --git a/buildSrc/scriptDepVersions.gradle b/buildSrc/scriptDepVersions.gradle
new file mode 100644
index 000000000000..c768243b960d
--- /dev/null
+++ b/buildSrc/scriptDepVersions.gradle
@@ -0,0 +1,16 @@
+// Declare script dependency versions outside of palantir's
+// version unification control. These are not our main dependencies
+// but are reused in buildSrc and across applied scripts.
+
+ext {
+  scriptDepVersions = [
+      "apache-rat": "0.11",
+      "commons-codec": "1.13",
+      "ecj": "3.25.0",
+      "flexmark": "0.61.24",
+      "icu": "68.2",
+      "javacc": "7.0.4",
+      "jflex": "1.7.0",
+      "jgit": "5.9.0.202009080501-r",
+  ]
+}
diff --git a/lucene/analysis/common/src/tools/groovy/generate-unicode-data.groovy b/gradle/generation/unicode-data.gradle
similarity index 65%
rename from lucene/analysis/common/src/tools/groovy/generate-unicode-data.groovy
rename to gradle/generation/unicode-data.gradle
index 37857e09b00f..4c18c1ee3786 100644
--- a/lucene/analysis/common/src/tools/groovy/generate-unicode-data.groovy
+++ b/gradle/generation/unicode-data.gradle
@@ -1,3 +1,6 @@
+import com.ibm.icu.lang.UCharacter;
+import com.ibm.icu.util.VersionInfo;
+
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
@@ -15,34 +18,36 @@
  * limitations under the License.
  */
 
-import com.ibm.icu.lang.UCharacter;
-import com.ibm.icu.util.VersionInfo;
+// Regenerates UnicodeProps.java
+configure(project(":lucene:analysis:common")) {
+  task generateUnicodeProps() {
+    def outputFile = file("src/java/org/apache/lucene/analysis/util/UnicodeProps.java")
 
-def linesep = properties['line.separator'];
+    def icuVersion = VersionInfo.ICU_VERSION.toString()
+    def unicodeVersion = UCharacter.getUnicodeVersion().toString()
 
-def appendChar = { StringBuilder sb, int c ->
-  int len = sb.length();
-  if (len != 0) {
-    sb.append(', ');
-  }
-  if (len == 0 || len - sb.lastIndexOf(linesep) > 100) {
-    sb.append(linesep).append('    ');
-  }
-  sb.append(String.format(Locale.ROOT, "0x%04X", c));
-}
+    inputs.property("icu-version", icuVersion)
+    inputs.property("unicode-version", unicodeVersion)
+    outputs.file outputFile
 
-def whitespace = new StringBuilder();
-for (int c = UCharacter.MIN_CODE_POINT; c <= UCharacter.MAX_CODE_POINT; c++) {
-  if (UCharacter.isUWhiteSpace(c)) {
-    appendChar(whitespace, c);
-  }
-}
+    doFirst {
+      def icuLockDepVersion = getVersion("com.ibm.icu", "icu4j")
+      def icuScriptDep = scriptDepVersions['icu']
+      if (icuLockDepVersion != icuScriptDep) {
+        throw new GradleException("ICU version in build script dependency ${icuScriptDep} and in" +
+            " project dependency ${icuLockDepVersion} must match.")
+      }
 
-def icuVersion = VersionInfo.ICU_VERSION.toString();
-def unicodeVersion = UCharacter.getUnicodeVersion().toString();
+      List<String> chars = []
+      for (int c = UCharacter.MIN_CODE_POINT; c <= UCharacter.MAX_CODE_POINT; c++) {
+        if (UCharacter.isUWhiteSpace(c)) {
+          chars.add(String.format(Locale.ROOT, "0x%04X", c))
+        }
+      }
+      def whitespace = chars.join(", ")
 
-def code = """
-// DO NOT EDIT THIS FILE! Use "ant unicode-data" to recreate.
+      def code = """
+// DO NOT EDIT THIS FILE! Use "gradlew generateUnicodeProps tidy" to recreate.
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -68,9 +73,7 @@ import org.apache.lucene.util.SparseFixedBitSet;
 
 /**
  * This file contains unicode properties used by various {@link CharTokenizer}s.
- * The data was created using ICU4J v${icuVersion}
- * <p>
- * Unicode version: ${unicodeVersion}
+ * The data was generated using ICU4J v${icuVersion}, unicode version: ${unicodeVersion}.
  */
 public final class UnicodeProps {
   private UnicodeProps() {}
@@ -80,7 +83,7 @@ public final class UnicodeProps {
   
   /** Bitset with Unicode WHITESPACE code points. */
   public static final Bits WHITESPACE = createBits(${whitespace});
-  
+
   private static Bits createBits(final int... codepoints) {
     final int len = codepoints[codepoints.length - 1] + 1;
     final SparseFixedBitSet bitset = new SparseFixedBitSet(len);
@@ -98,9 +101,10 @@ public final class UnicodeProps {
     };
   }
 }
-""";
-
-File f = new File(properties['unicode-props-file']);
-f.write(code.trim(), 'UTF-8');
+"""
+      outputFile.setText(code.trim(), "UTF-8")
+    }
+  }
 
-task.log("Unicode data written to: " + f);
+  regenerate.dependsOn wrapWithPersistentChecksums(generateUnicodeProps, [ andThenTasks: "spotlessApply" ])
+}
\ No newline at end of file
diff --git a/lucene/analysis/common/src/generated/checksums/generateUnicodeProps.json b/lucene/analysis/common/src/generated/checksums/generateUnicodeProps.json
new file mode 100644
index 000000000000..b72e91592b80
--- /dev/null
+++ b/lucene/analysis/common/src/generated/checksums/generateUnicodeProps.json
@@ -0,0 +1,3 @@
+{
+    "lucene/analysis/common/src/java/org/apache/lucene/analysis/util/UnicodeProps.java": "7d2cf5f959c2dfc5b83295e359212a1228f761c4"
+}
\ No newline at end of file
diff --git a/lucene/analysis/common/src/java/org/apache/lucene/analysis/util/UnicodeProps.java b/lucene/analysis/common/src/java/org/apache/lucene/analysis/util/UnicodeProps.java
index 777100b7438e..55c3f2f28726 100644
--- a/lucene/analysis/common/src/java/org/apache/lucene/analysis/util/UnicodeProps.java
+++ b/lucene/analysis/common/src/java/org/apache/lucene/analysis/util/UnicodeProps.java
@@ -1,4 +1,4 @@
-// DO NOT EDIT THIS FILE! Use "ant unicode-data" to recreate.
+// DO NOT EDIT THIS FILE! Use "gradlew generateUnicodeProps tidy" to recreate.
 
 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
@@ -24,15 +24,13 @@
 
 /**
  * This file contains unicode properties used by various {@link CharTokenizer}s. The data was
- * created using ICU4J v62.2.0.0
- *
- * <p>Unicode version: 11.0.0.0
+ * generated using ICU4J v68.2.0.0, unicode version: 13.0.0.0.
  */
 public final class UnicodeProps {
   private UnicodeProps() {}
 
   /** Unicode version that was used to generate this file: {@value} */
-  public static final String UNICODE_VERSION = "11.0.0.0";
+  public static final String UNICODE_VERSION = "13.0.0.0";
 
   /** Bitset with Unicode WHITESPACE code points. */
   public static final Bits WHITESPACE =