diff --git a/Changelog.md b/Changelog.md
index ce31f3b0..7493d8c1 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -8,6 +8,7 @@
 * Add `PriorityQueue` (#392).
 * Add support for Weak references (#388).
 * Clarify difference between `List` and `pure/List` in doc comments (#386).
+* Fix memory leak bugs in `List.addRepeat<T>` and `List.removeLast<T>` (#343).
 
 ## 1.0.0
 
diff --git a/src/List.mo b/src/List.mo
index 62755632..c9fcd5c1 100644
--- a/src/List.mo
+++ b/src/List.mo
@@ -162,7 +162,7 @@ module {
     var cnt = count;
     while (cnt > 0) {
       let db_size = data_block_size(list.blockIndex);
-      if (list.elementIndex == 0 and db_size <= cnt) {
+      if (list.elementIndex == 0 and db_size <= cnt and list.blocks[list.blockIndex].size() == 0) {
         list.blocks[list.blockIndex] := VarArray.repeat<?T>(?initValue, db_size);
         cnt -= db_size;
         list.blockIndex += 1
@@ -470,7 +470,7 @@ module {
 
       // Keep one totally empty block when removing
       if (blockIndex + 2 < list.blocks.size()) {
-        if (list.blocks[blockIndex + 2].size() == 0) {
+        if (list.blocks[blockIndex + 2].size() > 0) {
           list.blocks[blockIndex + 2] := [var]
         }
       };