diff --git a/common/src/main/java/org/implab/gradle/common/dsl/TaskEnvSpecMixin.java b/common/src/main/java/org/implab/gradle/common/dsl/TaskEnvSpecMixin.java
--- a/common/src/main/java/org/implab/gradle/common/dsl/TaskEnvSpecMixin.java
+++ b/common/src/main/java/org/implab/gradle/common/dsl/TaskEnvSpecMixin.java
@@ -35,7 +35,7 @@ public interface TaskEnvSpecMixin {
      * The configuration action is called immediately. To support lazy evaluation,
      * properties may be assigned to providers.
      */
-    default void env(Action<Map<String, ?>> configure) {
+    default void env(Action<Map<String, Object>> configure) {
         Properties.configureMap(getEnvironment(), configure, Object::toString);
     }
 
diff --git a/common/src/main/java/org/implab/gradle/common/utils/Closures.java b/common/src/main/java/org/implab/gradle/common/utils/Closures.java
--- a/common/src/main/java/org/implab/gradle/common/utils/Closures.java
+++ b/common/src/main/java/org/implab/gradle/common/utils/Closures.java
@@ -24,7 +24,7 @@ public final class Closures {
 
     public static void apply(Closure<?> action, Object target) {
         var c = (Closure<?>)action.clone();
-        c.setResolveStrategy(0);
+        c.setResolveStrategy(Closure.DELEGATE_FIRST);
         c.setDelegate(target);
         c.call(target);
 
diff --git a/common/src/main/java/org/implab/gradle/common/utils/Properties.java b/common/src/main/java/org/implab/gradle/common/utils/Properties.java
--- a/common/src/main/java/org/implab/gradle/common/utils/Properties.java
+++ b/common/src/main/java/org/implab/gradle/common/utils/Properties.java
@@ -49,13 +49,13 @@ public final class Properties {
         });
     }
 
-    public static <K> void configureMap(MapProperty<K, Object> prop, Action<Map<K, ?>> configure) {
+    public static <K> void configureMap(MapProperty<K, Object> prop, Action<Map<K, Object>> configure) {
         var map = new HashMap<K, Object>();
         configure.execute(map);
         mergeMap(prop, map);
     }
 
-    public static <K, V> void configureMap(MapProperty<K, V> prop, Action<Map<K, ?>> configure, Function<Object, V> mapper) {
+    public static <K, V> void configureMap(MapProperty<K, V> prop, Action<Map<K, Object>> configure, Function<Object, V> mapper) {
         var map = new HashMap<K, Object>();
         configure.execute(map);
         mergeMap(prop, map, mapper);