diff --git a/storm/Atomic.cpp b/storm/Atomic.cpp
new file mode 100644
index 0000000..2031bfc
--- /dev/null
+++ b/storm/Atomic.cpp
@@ -0,0 +1,25 @@
+#include "storm/Atomic.hpp"
+
+#if defined(WHOA_SYSTEM_WIN)
+#include <windows.h>
+#endif
+
+int32_t SInterlockedDecrement(int32_t* ptr) {
+#if defined(WHOA_SYSTEM_WIN)
+    return InterlockedDecrement(ptr);
+#endif
+
+#if defined(WHOA_SYSTEM_MAC) || defined(WHOA_SYSTEM_LINUX)
+    return __sync_fetch_and_sub(ptr, 1) - 1;
+#endif
+}
+
+int32_t SInterlockedIncrement(int32_t* ptr) {
+#if defined(WHOA_SYSTEM_WIN)
+    return InterlockedIncrement(ptr);
+#endif
+
+#if defined(WHOA_SYSTEM_MAC) || defined(WHOA_SYSTEM_LINUX)
+    return __sync_fetch_and_add(ptr, 1) + 1;
+#endif
+}
diff --git a/storm/Atomic.hpp b/storm/Atomic.hpp
new file mode 100644
index 0000000..58ce744
--- /dev/null
+++ b/storm/Atomic.hpp
@@ -0,0 +1,10 @@
+#ifndef STORM_ATOMIC_HPP
+#define STORM_ATOMIC_HPP
+
+#include <cstdint>
+
+int32_t SInterlockedDecrement(int32_t* ptr);
+
+int32_t SInterlockedIncrement(int32_t* ptr);
+
+#endif
diff --git a/test/Atomic.cpp b/test/Atomic.cpp
new file mode 100644
index 0000000..205c9cd
--- /dev/null
+++ b/test/Atomic.cpp
@@ -0,0 +1,20 @@
+#include "storm/Atomic.hpp"
+#include "test/Test.hpp"
+
+TEST_CASE("SInterlockedDecrement", "[atomic]") {
+    SECTION("decrements value") {
+        int32_t value = 1;
+        auto decremented = SInterlockedDecrement(&value);
+        CHECK(value == 0);
+        CHECK(decremented == 0);
+    }
+}
+
+TEST_CASE("SInterlockedIncrement", "[atomic]") {
+    SECTION("increments value") {
+        int32_t value = { 1 };
+        auto incremented = SInterlockedIncrement(&value);
+        CHECK(value == 2);
+        CHECK(incremented == 2);
+    }
+}