diff --git a/CMakePresets.json b/CMakePresets.json
index 19060b1c73..1460b39d06 100644
--- a/CMakePresets.json
+++ b/CMakePresets.json
@@ -25,10 +25,12 @@
       "name": "sanitize",
       "displayName": "Sanitize build config",
       "cacheVariables": {
-        "LEAN_EXTRA_CXX_FLAGS": "-fsanitize=address,undefined",
-        "LEANC_EXTRA_CC_FLAGS": "-fsanitize=address,undefined -fsanitize-link-c++-runtime",
+        "LEAN_EXTRA_CXX_FLAGS": "-fsanitize=address,undefined -DLEAN_DEFAULT_THREAD_STACK_SIZE=16*1024*1024",
+        "LEANC_EXTRA_CC_FLAGS": "-fsanitize=address,undefined",
+        "LEAN_EXTRA_LINKER_FLAGS": "-fsanitize=address,undefined -fsanitize-link-c++-runtime",
         "SMALL_ALLOCATOR": "OFF",
-        "BSYMBOLIC": "OFF"
+        "BSYMBOLIC": "OFF",
+        "LEAN_TEST_VARS": "MAIN_STACK_SIZE=16000"
       },
       "generator": "Unix Makefiles",
       "binaryDir": "${sourceDir}/build/sanitize"
diff --git a/src/runtime/io.cpp b/src/runtime/io.cpp
index 369e6b9738..b1c7aa7190 100644
--- a/src/runtime/io.cpp
+++ b/src/runtime/io.cpp
@@ -1465,7 +1465,18 @@ extern "C" LEAN_EXPORT obj_res lean_runtime_mark_persistent(obj_arg a, obj_arg /
     return io_result_mk_ok(a);
 }
 
-extern "C" LEAN_EXPORT obj_res lean_runtime_forget(obj_arg /* a */, obj_arg /* w */) {
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#include <sanitizer/lsan_interface.h>
+#endif
+#endif
+
+extern "C" LEAN_EXPORT obj_res lean_runtime_forget(obj_arg o, obj_arg /* w */) {
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+    __lsan_ignore_object(o);
+#endif
+#endif
     return io_result_mk_ok(box(0));
 }
 
diff --git a/tests/common.sh b/tests/common.sh
index 6340d73c8a..04e5522453 100644
--- a/tests/common.sh
+++ b/tests/common.sh
@@ -1,6 +1,6 @@
 set -euo pipefail
 
-ulimit -s 8192
+ulimit -s ${MAIN_STACK_SIZE:-8192}
 DIFF=diff
 if diff --color --help >/dev/null 2>&1; then
     DIFF="diff --color";