diff --git a/build.gradle b/build.gradle
index 904f04b..5ee390d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -11,8 +11,8 @@ repositories {
 }
 
 dependencies {
-    compile group: 'org.bouncycastle', name: 'bcmail-jdk15on', version: '1.52'
-    compile group: 'org.bouncycastle', name: 'bcprov-jdk15on', version: '1.52'
+    compile group: 'org.bouncycastle', name: 'bcmail-jdk15on', version: '1.53'
+    compile group: 'org.bouncycastle', name: 'bcprov-jdk15on', version: '1.53'
     compile group: 'javax.mail', name: 'mail', version: '1.4.4'
     testCompile group: 'junit', name: 'junit', version: '3.8.1'
 }
diff --git a/pom.xml b/pom.xml
index 7a04553..c50fa9e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -55,12 +55,12 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
         <dependency>
             <groupId>org.bouncycastle</groupId>
             <artifactId>bcmail-jdk15on</artifactId>
-            <version>1.50</version>
+            <version>1.53</version>
         </dependency>
         <dependency>
             <groupId>org.bouncycastle</groupId>
             <artifactId>bcprov-jdk15on</artifactId>
-            <version>1.50</version>
+            <version>1.53</version>
         </dependency>
         <dependency>
         <groupId>javax.mail</groupId>