diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9fd45e0..e352d7b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -20,3 +20,15 @@ jobs:
       run: cargo build --verbose
     - name: Run tests
       run: cargo test --verbose
+    - name: Install Valgrind
+      run: sudo apt-get update && sudo apt-get install -y valgrind
+    - name: memcheck
+      run: |
+        cargo test -p rtree-capi c_api -- --nocapture
+        LD_LIBRARY_PATH=target/debug valgrind \
+          --tool=memcheck \
+          --leak-check=full \
+          --show-leak-kinds=all \
+          --track-origins=yes \
+          --error-exitcode=99 \
+          target/debug/test_c_api
diff --git a/rtree-capi/src/node.rs b/rtree-capi/src/node.rs
index 3a89ec2..d366c98 100644
--- a/rtree-capi/src/node.rs
+++ b/rtree-capi/src/node.rs
@@ -147,6 +147,11 @@ pub extern "C" fn rtree_node_children_free(children: *mut *mut RTreeNodeH, n: us
     if children.is_null() {
         return RTreeError::NullPointer;
     }
-    drop(unsafe { Vec::from_raw_parts(children, n, n) });
+    let child_ptrs = unsafe { Vec::from_raw_parts(children, n, n) };
+    for child in child_ptrs {
+        if !child.is_null() {
+            drop(unsafe { Box::from_raw(child as *mut NodeRef) });
+        }
+    }
     RTreeError::Success
 }
diff --git a/rtree-capi/tests/test.c b/rtree-capi/tests/test.c
index 1743eb7..5e28876 100644
--- a/rtree-capi/tests/test.c
+++ b/rtree-capi/tests/test.c
@@ -199,6 +199,7 @@ bool test_nodes(void) {
         rtree_free(tree);
         return false;
     }
+    rtree_node_children_free(child1children, nchild1children);
 
     rtree_node_children_free(children, nchildren);
     rtree_node_free(root);
@@ -225,6 +226,8 @@ bool test_root_node_id(void) {
         rtree_free(tree);
         return false;
     }
+    rtree_node_free(root);
+    rtree_free(tree);
     return true;
 }
 
@@ -372,6 +375,7 @@ bool test_rtree_node_1d(void) {
         rtree_free(tree);
         return false;
     }
+    rtree_node_children_free(child1children, nchild1children);
 
     rtree_node_children_free(children, nchildren);
     rtree_node_free(root);