diff --git a/subprojects/parseq/build.gradle b/subprojects/parseq/build.gradle
index 2f78b0de..d26e5a37 100644
--- a/subprojects/parseq/build.gradle
+++ b/subprojects/parseq/build.gradle
@@ -35,6 +35,7 @@ configurations {
 }
 
 dependencies {
+  compile group: 'com.google.code.findbugs', name: 'jsr305', version: '3.0.2'
   compile group: 'org.codehaus.jackson', name: 'jackson-core-asl', version: '1.8.8'
   compile group: 'org.codehaus.jackson', name: 'jackson-mapper-asl', version: '1.8.8'
   compile group: "org.slf4j", name: "slf4j-api", version: "1.7.25"
diff --git a/subprojects/parseq/src/main/java/com/linkedin/parseq/Task.java b/subprojects/parseq/src/main/java/com/linkedin/parseq/Task.java
index bf39132e..2f97cd28 100644
--- a/subprojects/parseq/src/main/java/com/linkedin/parseq/Task.java
+++ b/subprojects/parseq/src/main/java/com/linkedin/parseq/Task.java
@@ -26,6 +26,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
 
+import javax.annotation.Nonnull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -184,7 +185,8 @@ default <R> Task<R> apply(final String desc, final PromisePropagator<T, R> propa
    * @param func function to be applied to successful result of this task.
    * @return a new task which will apply given function on result of successful completion of this task
    */
-  default <R> Task<R> map(final String desc, final Function1<? super T, ? extends R> func) {
+  @Nonnull
+  default <R> Task<R> map(@Nonnull final String desc, @Nonnull final Function1<? super T, ? extends R> func) {
     ArgumentUtil.requireNotNull(func, "function");
     return apply(desc, new PromiseTransformer<T, R>(func));
   }
@@ -193,7 +195,8 @@ default <R> Task<R> map(final String desc, final Function1<? super T, ? extends
    * Equivalent to {@code map("map", func)}.
    * @see #map(String, Function1)
    */
-  default <R> Task<R> map(final Function1<? super T, ? extends R> func) {
+  @Nonnull
+  default <R> Task<R> map(@Nonnull final Function1<? super T, ? extends R> func) {
     return map("map: " + _taskDescriptor.getDescription(func.getClass().getName()), func);
   }