diff --git a/transpiler/src/main/java/org/jsweet/transpiler/extension/RemoveJavaDependenciesAdapter.java b/transpiler/src/main/java/org/jsweet/transpiler/extension/RemoveJavaDependenciesAdapter.java
index 13846162..8ccc2693 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/extension/RemoveJavaDependenciesAdapter.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/extension/RemoveJavaDependenciesAdapter.java
@@ -1056,13 +1056,15 @@ public class RemoveJavaDependenciesAdapter extends Java2TypeScriptAdapter {
 		case "remove":
 		case "removeElement":
 			printMacroName(targetMethodName);
-			if (Util.isNumber(invocation.getArgument(0).getType())) {
+			if (Util.isNumber(invocation.getArgument(0).getType()) && types()
+					.isSubtype(invocation.getMethod().getEnclosingElement().asType(), util().getType(List.class))) {
 				print(invocation.getTargetExpression(), delegate).print(".splice(")
 						.printArgList(invocation.getArguments()).print(", 1)");
 			} else {
-				print("(a => a.splice(a.indexOf(").print(invocation.getArgument(0)).print(")")
-						.print(invocation.getArgumentCount() == 1 ? "" : ", ")
-						.printArgList(invocation.getArgumentTail()).print(", 1))(");
+				print("(a => { let index = a.indexOf(").print(invocation.getArgument(0))
+						.print("); if(index>=0) { a.splice(index").print(invocation.getArgumentCount() == 1 ? "" : ", ")
+						.printArgList(invocation.getArgumentTail())
+						.print(", 1); return true; } else { return false; }})(");
 				print(invocation.getTargetExpression(), delegate).print(")");
 			}
 			return true;
@@ -1109,7 +1111,8 @@ public class RemoveJavaDependenciesAdapter extends Java2TypeScriptAdapter {
 			return true;
 		case "size":
 			printMacroName(targetMethodName);
-			print(invocation.getTargetExpression(), delegate).print(".length");
+			print("(<number>");
+			print(invocation.getTargetExpression(), delegate).print(".length)");
 			return true;
 		case "get":
 		case "elementAt":
diff --git a/transpiler/src/main/java/org/jsweet/transpiler/model/support/UtilSupport.java b/transpiler/src/main/java/org/jsweet/transpiler/model/support/UtilSupport.java
index bf7d2d30..bc03b273 100644
--- a/transpiler/src/main/java/org/jsweet/transpiler/model/support/UtilSupport.java
+++ b/transpiler/src/main/java/org/jsweet/transpiler/model/support/UtilSupport.java
@@ -93,6 +93,8 @@ public class UtilSupport implements Util {
 			return context.symtab.noSuchFieldErrorType;
 		case "java.lang.Throwable":
 			return context.symtab.throwableType;
+		case "java.util.List":
+			return context.symtab.listType;
 		}
 		return null;
 	}
diff --git a/transpiler/src/test/java/source/nativestructures/Maps.java b/transpiler/src/test/java/source/nativestructures/Maps.java
index 274a94bf..859d9fbc 100644
--- a/transpiler/src/test/java/source/nativestructures/Maps.java
+++ b/transpiler/src/test/java/source/nativestructures/Maps.java
@@ -73,6 +73,24 @@ public class Maps {
 			trace.push("" + e.getValue());
 		}
 		
+		Map<String, Integer> m3 = new HashMap<>();
+		m3.put("a", 1);
+		assert m3.size() == 1;
+		m3.remove("a");
+		assert m3.size() == 0;
+		m3.put("b", 2);
+		m3.remove("a");
+		assert m3.size() == 1;
+
+		Map<Integer, Integer> m4 = new HashMap<>();
+		m4.put(1, 1);
+		assert m4.size() == 1;
+		m4.remove(1);
+		assert m4.size() == 0;
+		m4.put(2, 2);
+		m4.remove(1);
+		assert m4.size() == 1;
+		
 		$export("trace", trace.join(","));
 
 	}
diff --git a/transpiler/src/test/java/source/nativestructures/Sets.java b/transpiler/src/test/java/source/nativestructures/Sets.java
index 552dac82..5a2a94b2 100644
--- a/transpiler/src/test/java/source/nativestructures/Sets.java
+++ b/transpiler/src/test/java/source/nativestructures/Sets.java
@@ -21,6 +21,25 @@ public class Sets {
 		System.out.println(map.get(s));
 		// TODO: make this work (see #196)
 		// assert "bye".equals(map.get(s));
+
+		Set<String> s3 = new HashSet<>();
+		s3.add("1");
+		assert s3.size() == 1;
+		assert s3.remove("1");
+		assert s3.size() == 0;
+		s3.add("2");
+		assert !s3.remove("1");
+		assert s3.size() == 1;
+
+		Set<Integer> s4 = new HashSet<>();
+		s4.add(1);
+		assert s4.size() == 1;
+		assert s4.remove(1);
+		assert s4.size() == 0;
+		s4.add(2);
+		assert !s4.remove(1);
+		assert s4.size() == 1;
+		
 	}
 
 }