1 files changed, 7 insertions, 3 deletions
diff --git a/src/main/java/au/id/zancanaro/javacheck/Generators.java b/src/main/java/au/id/zancanaro/javacheck/Generators.java
index 548bd29..4049149 100644
--- a/src/main/java/au/id/zancanaro/javacheck/Generators.java
+++ b/src/main/java/au/id/zancanaro/javacheck/Generators.java
@@ -91,10 +91,12 @@ public final class Generators {
         return (random, size) -> {
             Generator<Integer> countGen = sized(s -> integer(minElements, maxElements));
             int count = countGen.generate(random, size).getValue();
-            return Generator.list(count, gen).generate(random, size)
+            return Generator.list(count, gen)
+                    .generate(random, size)
                     .filter(list ->
                             minElements <= list.size()
-                                    && list.size() < maxElements);
+                                    && list.size() < maxElements)
+                    .map(Collections::unmodifiableList);
         };
     }
 
@@ -102,7 +104,9 @@ public final class Generators {
         return (random, size) -> {
             Generator<Integer> countGen = sized(s -> integer(0, s));
             int count = countGen.generate(random, size).getValue();
-            return Generator.list(count, gen).generate(random, size);
+            return Generator.list(count, gen)
+                    .generate(random, size)
+                    .map(Collections::unmodifiableList);
         };
     }