diff --git a/gradle/core/build.gradle b/gradle/core/build.gradle
index 6e0dbe500..8947ad94c 100644
--- a/gradle/core/build.gradle
+++ b/gradle/core/build.gradle
@@ -272,6 +272,16 @@ dependencies {
 }
 
 task jaxbToJava {
+  def xsdFilesDir = "${javaDir}/google/registry/xml/xsd"
+  def bindingsFile = "${javaDir}/google/registry/xjc/bindings.xjb"
+  def pkgInfoGenerator = "${javaDir}/google/registry/xjc/make_pkginfo.sh"
+  def pkgInfoTemplate = "${javaDir}/google/registry/xjc/package-info.java.in"
+  def outputDir = "${generatedDir}/google/registry/xjc"
+
+  inputs.dir xsdFilesDir
+  inputs.files bindingsFile, pkgInfoTemplate, pkgInfoGenerator
+  outputs.dir outputDir
+
   doLast {
     file(generatedDir).mkdirs()
 
@@ -281,30 +291,29 @@ task jaxbToJava {
     def xjcTempSourceDir = file("${temporaryDir}/xjc")
     xjcTempSourceDir.mkdirs()
     ant.copy(
-        todir: "${xjcTempSourceDir}",
-        overwrite: true) {
+            todir: "${xjcTempSourceDir}",
+            overwrite: true) {
       fileSet(
-          dir: "${javaDir}/google/registry/xml/xsd",
-          includes: '**.xsd')
+              dir: xsdFilesDir,
+              includes: '**.xsd')
     }
     ant.copy(
-        todir: "${xjcTempSourceDir}",
-        overwrite: true,
-        file:
-            "${javaDir}/google/registry/xjc/bindings.xjb")
+            todir: "${xjcTempSourceDir}",
+            overwrite: true,
+            file: bindingsFile)
 
     ant.taskdef(
-        name: 'xjc',
-        classname: 'com.sun.tools.xjc.XJCTask',
-        classpath: configurations.jaxb.asPath)
+            name: 'xjc',
+            classname: 'com.sun.tools.xjc.XJCTask',
+            classpath: configurations.jaxb.asPath)
     ant.xjc(
-        destdir: "${generatedDir}",
-        binding: "${xjcTempSourceDir}/bindings.xjb",
-        removeOldOutput: 'yes', extension: 'true') {
+            destdir: "${generatedDir}",
+            binding: "${xjcTempSourceDir}/bindings.xjb",
+            removeOldOutput: 'yes', extension: 'true') {
       project.fileTree(
-          dir: new File("$xjcTempSourceDir"),
-          include: ['**/*.xsd'])
-          .addToAntBuilder(ant, 'schema', FileCollection.AntType.FileSet)
+              dir: new File("$xjcTempSourceDir"),
+              include: ['**/*.xsd'])
+              .addToAntBuilder(ant, 'schema', FileCollection.AntType.FileSet)
       // -npa: do not generate package-info.java files. They will be generated
       // below.
       arg(line: '-npa -quiet -extension')
@@ -312,57 +321,75 @@ task jaxbToJava {
     exec {
       workingDir "${generatedDir}"
 
-      executable "${javaDir}/google/registry/xjc/make_pkginfo.sh"
-      args "${javaDir}/google/registry/xjc/package-info.java.in",
-          "${generatedDir}/google/registry/xjc"
+      executable pkgInfoGenerator
+      args pkgInfoTemplate, outputDir
     }
   }
 }
 
 task soyToJava {
+  // Relative paths of soy directories.
+  def spec11SoyDir = "google/registry/reporting/spec11/soy"
+  def toolsSoyDir = "google/registry/tools/soy"
+  def uiSoyDir = "google/registry/ui/soy"
+  def registrarSoyDir = "google/registry/ui/soy/registrar"
+
+  def soyRelativeDirs = [
+          spec11SoyDir, toolsSoyDir, uiSoyDir, registrarSoyDir,
+  ]
+  soyRelativeDirs.each {
+    inputs.dir "${javaDir}/${it}"
+    outputs.dir "${generatedDir}/${it}"
+  }
+
   ext.soyToJava = { javaPackage, outputDirectory, soyFiles ->
     javaexec {
       main = "com.google.template.soy.SoyParseInfoGenerator"
       classpath configurations.soy
       args "--javaPackage", "${javaPackage}",
-          "--outputDirectory", "${outputDirectory}",
-          "--javaClassNameSource", "filename",
-          "--allowExternalCalls", "true",
-          "--srcs", "${soyFiles.join(',')}"
+              "--outputDirectory", "${outputDirectory}",
+              "--javaClassNameSource", "filename",
+              "--allowExternalCalls", "true",
+              "--srcs", "${soyFiles.join(',')}"
     }
   }
 
   doLast {
 
     soyToJava('google.registry.tools.soy',
-        "${generatedDir}/google/registry/tools/soy",
-        fileTree(
-            dir: "${javaDir}/google/registry/tools/soy",
-            include: ['**/*.soy']))
+            "${generatedDir}/${toolsSoyDir}",
+            fileTree(
+                    dir: "${javaDir}/${toolsSoyDir}",
+                    include: ['**/*.soy']))
 
     soyToJava('google.registry.ui.soy.registrar',
-        "${generatedDir}/google/registry/ui/soy/registrar",
-        fileTree(
-            dir: "${javaDir}/google/registry/ui/soy/registrar",
-            include: ['**/*.soy']))
+            "${generatedDir}/${registrarSoyDir}",
+            fileTree(
+                    dir: "${javaDir}/${registrarSoyDir}",
+                    include: ['**/*.soy']))
 
     soyToJava('google.registry.ui.soy',
-        "${generatedDir}/google/registry/ui/soy",
-        files {
-          file("${javaDir}/google/registry/ui/soy").listFiles()
-        }.filter {
-          it.name.endsWith(".soy")
-        })
+            "${generatedDir}/${uiSoyDir}",
+            files {
+              file("${javaDir}/${uiSoyDir}").listFiles()
+            }.filter {
+              it.name.endsWith(".soy")
+            })
 
     soyToJava('google.registry.reporting.spec11.soy',
-        "${generatedDir}/google/registry/reporting/spec11/soy",
-        fileTree(
-            dir: "${javaDir}/google/registry/reporting/spec11/soy",
-            include: ['**/*.soy']))
+            "${generatedDir}/${spec11SoyDir}",
+            fileTree(
+                    dir: "${javaDir}/${spec11SoyDir}",
+                    include: ['**/*.soy']))
   }
 }
 
 task stylesheetsToJavascript {
+  def cssSourceDir = "${javaDir}/google/registry/ui/css"
+  def outputDir = "${project.buildDir}/resources/main/google/registry/ui/css"
+  inputs.dir cssSourceDir
+  outputs.dir outputDir
+
   ext.cssCompile = { outputName, debug, cssFiles ->
     javaexec {
       main = "com.google.common.css.compiler.commandline.ClosureCommandLineCompiler"
@@ -388,8 +415,6 @@ task stylesheetsToJavascript {
   }
 
   doLast {
-    def cssSourceDir = "${javaDir}/google/registry/ui/css"
-    def outputDir = "${project.buildDir}/resources/main/google/registry/ui/css"
     file("${outputDir}").mkdirs()
     def srcFiles = [
         "${cssSourceDir}/console.css",