diff --git a/core/build.gradle b/core/build.gradle
index a72324098..53ec7d874 100644
--- a/core/build.gradle
+++ b/core/build.gradle
@@ -27,6 +27,7 @@ dependencies {
 sourceCompatibility = 1.7
 compileJava.options.encoding = 'UTF-8'
 compileTestJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
 
 protobuf {
     protoc {
diff --git a/examples/build.gradle b/examples/build.gradle
index 1ff80e682..039fb1a74 100644
--- a/examples/build.gradle
+++ b/examples/build.gradle
@@ -14,3 +14,4 @@ dependencies {
 sourceCompatibility = 1.8
 compileJava.options.encoding = 'UTF-8'
 compileTestJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
diff --git a/tools/build.gradle b/tools/build.gradle
index f6a030163..e114d78e4 100644
--- a/tools/build.gradle
+++ b/tools/build.gradle
@@ -13,6 +13,7 @@ dependencies {
 sourceCompatibility = 1.8
 compileJava.options.encoding = 'UTF-8'
 compileTestJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
 
 task wallet_tool(type: JavaExec) {
     description = 'Print and manipulate wallets.'
diff --git a/wallettemplate/build.gradle b/wallettemplate/build.gradle
index 556af7e11..ff1dabae9 100644
--- a/wallettemplate/build.gradle
+++ b/wallettemplate/build.gradle
@@ -20,5 +20,6 @@ javafx {
 sourceCompatibility = 1.11
 compileJava.options.encoding = 'UTF-8'
 compileTestJava.options.encoding = 'UTF-8'
+javadoc.options.encoding = 'UTF-8'
 
 mainClassName = 'wallettemplate.Main'