diff --git a/.gitignore b/.gitignore
index da66384..8b18661 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,15 @@
+# gradle files.
 .gradle/
 build/
 gradle.properties
+
+# eclipse files.
+.settings/
 .classpath
 .project
-.settings/
+
+# intellij files.
+.idea/
+*.iml
+*.ipr
+*.iws
diff --git a/reactfx/src/main/java/org/reactfx/value/Val.java b/reactfx/src/main/java/org/reactfx/value/Val.java
index 060afb7..9559f9d 100644
--- a/reactfx/src/main/java/org/reactfx/value/Val.java
+++ b/reactfx/src/main/java/org/reactfx/value/Val.java
@@ -455,13 +455,13 @@ static <T, U> Val<U> mapDynamic(
     static <T, U> Val<U> flatMap(
             ObservableValue<T> src,
             Function<? super T, ? extends ObservableValue<U>> f) {
-        return new FlatMappedVal<>(src, f);
+        return new FlatMappedVal<>(src, (Function) f);
     }
 
     static <T, U> Var<U> selectVar(
             ObservableValue<T> src,
             Function<? super T, ? extends Property<U>> f) {
-        return new FlatMappedVar<>(src, f);
+        return new FlatMappedVar<>(src, (Function) f);
     }
 
     static <T, U> Var<U> selectVar(