diff --git a/src/free.cpp b/src/free.cpp
index b4f0a6a..da29fd2 100644
--- a/src/free.cpp
+++ b/src/free.cpp
@@ -3,6 +3,12 @@
 namespace mem
 {
 
-void free(void* ptr) { (void)ptr; }
+void free(void* ptr)
+{
+    if (ptr == nullptr)
+    {
+        return;
+    }
+}
 
 } // namespace mem
diff --git a/tests/unit/test_free.cpp b/tests/unit/test_free.cpp
new file mode 100644
index 0000000..a58b158
--- /dev/null
+++ b/tests/unit/test_free.cpp
@@ -0,0 +1,9 @@
+#include "malloc_from_scratch/memory_allocator.h"
+#include "test_utils.h"
+
+int main()
+{
+    mem::free(nullptr);
+
+    TEST_PASS();
+}