diff --git a/storm/Core.cpp b/storm/Core.cpp
new file mode 100644
index 0000000..11eb35a
--- /dev/null
+++ b/storm/Core.cpp
@@ -0,0 +1,27 @@
+#include "Core.hpp"
+#include "Event.hpp"
+
+int32_t STORMAPI StormDestroy() {
+    // Combined list of all calls from every game
+
+    // SErrSetBlizzardErrorFunction(nullptr);
+    // SDlgDestroy();
+    // SGdiDestroy();
+    // SVidDestroy();
+    // SDrawDestroy();
+    // SRgnDestroy();
+    // SMsgDestroy();
+    // SNetDestroy();
+    SEvtDestroy();
+    // SBltDestroy();
+    // SCodeDestroy();
+    // SCmdDestroy();
+    // SFileDestroy();
+    // SCompDestroy();
+    // SStrDestroy();
+    // SRegDestroy();
+    // SErrDestroy();
+    // SLogDestroy();
+    // STransDestroy();
+    return 1;
+}
diff --git a/storm/Core.hpp b/storm/Core.hpp
index be2a0e8..613eae3 100644
--- a/storm/Core.hpp
+++ b/storm/Core.hpp
@@ -13,5 +13,6 @@
 #endif
 #endif
 
+int32_t STORMAPI StormDestroy();
 
 #endif
diff --git a/test/Big.cpp b/test/Big.cpp
index 82b9e1d..82fbcef 100644
--- a/test/Big.cpp
+++ b/test/Big.cpp
@@ -1,5 +1,4 @@
-#include "storm/Big.hpp"
-#include "test/Test.hpp"
+#include "BigTest.hpp"
 #include <string>
 
 TEST_CASE("SBigAdd", "[big]") {
diff --git a/test/BigTest.hpp b/test/BigTest.hpp
new file mode 100644
index 0000000..3e57cb3
--- /dev/null
+++ b/test/BigTest.hpp
@@ -0,0 +1,18 @@
+#include "Test.hpp"
+#include "storm/Big.hpp"
+
+class BigData;
+
+// Fixture for repetitive handling of BigData objects.
+struct BigDataTest {
+    using BigDataPtr = BigData*;
+
+    BigData* num;
+
+    BigDataTest() { SBigNew(&num); }
+    ~BigDataTest() { SBigDel(num); }
+
+    BigData** operator &() { return &num; }
+    operator BigDataPtr() const { return num; }
+    BigData* operator->() const { return num; }
+};
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 7e07469..1f3ba04 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -2,7 +2,9 @@
 if(WHOA_TEST_STORMDLL)
     set(TEST_SOURCES
         #Big.cpp
-        #Event.cpp
+        Core.cpp
+        Event.cpp
+        EventTest.cpp
         Memory.cpp
         Region.cpp
         String.cpp
diff --git a/test/Core.cpp b/test/Core.cpp
new file mode 100644
index 0000000..c6703d1
--- /dev/null
+++ b/test/Core.cpp
@@ -0,0 +1,40 @@
+#include "test/Test.hpp"
+#include "EventTest.hpp"
+#include "storm/Core.hpp"
+
+
+TEST_CASE("StormDestroy", "[core]") {
+    SECTION("always returns 1") {
+        CHECK(StormDestroy() == 1);
+    }
+
+    SECTION("SEvt") {
+        EventHandlerTest test;
+
+        SECTION("destroys all event handlers") {
+            SEvtRegisterHandler(1, 1, 1, 0, &TestEventHandler1);
+            CHECK(SEvtDispatch(1, 1, 1, nullptr) == 1);
+            CHECK(test.NumCalls() == 1);
+
+            CHECK(SEvtDispatch(1, 1, 1, nullptr) == 1);
+            CHECK(test.NumCalls() == 2);
+
+            CHECK(StormDestroy() == 1);
+
+            // Can't increment calls since the handler was destroyed
+            CHECK(SEvtDispatch(1, 1, 1, nullptr) == 0);
+            CHECK(test.NumCalls() == 2);
+        }
+
+        SECTION("doesn't destroy break data") {
+            // not ideal but it's official behaviour
+            SEvtBreakHandlerChain(nullptr);
+
+            CHECK(StormDestroy() == 1);
+
+            SEvtRegisterHandler(0, 0, 0, 0, &TestEventHandler1);
+            CHECK(SEvtDispatch(0, 0, 0, nullptr) == 0);
+            CHECK(SEvtDispatch(0, 0, 0, nullptr) == 1);
+        }
+    }
+}
diff --git a/test/Event.cpp b/test/Event.cpp
index dbd34cb..0b8a687 100644
--- a/test/Event.cpp
+++ b/test/Event.cpp
@@ -10,8 +10,7 @@ static void STORMAPI TestBreakEventHandlerSelf(void* data) {
 static void STORMAPI TestBreakEventHandlerOther(void* data) {
     EventHandlerTest::RegisterCall(10, data);
 
-    int bunk = 0;
-    CHECK(SEvtBreakHandlerChain(&bunk) == 1);
+    CHECK(SEvtBreakHandlerChain(nullptr) == 1);
 }
 
 TEST_CASE("SEvtBreakHandlerChain", "[event]") {
@@ -22,6 +21,7 @@ TEST_CASE("SEvtBreakHandlerChain", "[event]") {
 
         SEvtRegisterHandler(7357, 1, 0, 0, &TestEventHandler1);
         CHECK(SEvtDispatch(7357, 1, 0, nullptr) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, nullptr) == 1);
     }
 
     SECTION("causes SEvtDispatch to break early if one of many data matches") {
@@ -34,6 +34,11 @@ TEST_CASE("SEvtBreakHandlerChain", "[event]") {
 
         SEvtRegisterHandler(7357, 1, 0, 0, &TestEventHandler1);
         CHECK(SEvtDispatch(7357, 1, 0, &data2) == 0);
+
+        // CLEANUP - SEvtDestroy doesn't erase registered breaks, avoid polluting other tests
+        CHECK(SEvtDispatch(7357, 1, 0, nullptr) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, &data1) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, &data3) == 0);
     }
 
     SECTION("doesn't break SEvtDispatch if no data matches") {
@@ -46,6 +51,12 @@ TEST_CASE("SEvtBreakHandlerChain", "[event]") {
 
         SEvtRegisterHandler(7357, 1, 0, 0, &TestEventHandler1);
         CHECK(SEvtDispatch(7357, 1, 0, &test) == 1);
+
+        // CLEANUP - SEvtDestroy doesn't erase registered breaks, avoid polluting other tests
+        CHECK(SEvtDispatch(7357, 1, 0, nullptr) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, &data1) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, &data2) == 0);
+        CHECK(SEvtDispatch(7357, 1, 0, &data3) == 0);
     }
 
     SECTION("deduplicates multiple same-data breaks") {
@@ -75,15 +86,20 @@ TEST_CASE("SEvtBreakHandlerChain", "[event]") {
         SEvtRegisterHandler(0, 0, 0, 0, &TestBreakEventHandlerOther);
         SEvtRegisterHandler(0, 0, 0, 0, &TestEventHandler2);
 
-        CHECK(SEvtDispatch(0, 0, 0, nullptr) == 1);
+        int data = 42;
+        CHECK(SEvtDispatch(0, 0, 0, &data) == 1);
         CHECK(test.NumCalls() == 3);
         // Calls are reverse order, TestEventHandler1 doesn't get called
-        CHECK_THAT(test.CallResult(), MatchesCall({ 2, nullptr }));
-        CHECK_THAT(test.CallResult(), MatchesCall({ 10, nullptr }));
-        CHECK_THAT(test.CallResult(), MatchesCall({ 1, nullptr }));
+        CHECK_THAT(test.CallResult(), MatchesCall({ 2, &data }));
+        CHECK_THAT(test.CallResult(), MatchesCall({ 10, &data }));
+        CHECK_THAT(test.CallResult(), MatchesCall({ 1, &data }));
+
+        // CLEANUP - SEvtDestroy doesn't erase registered breaks, avoid polluting other tests
+        CHECK(SEvtDispatch(0, 0, 0, nullptr) == 0);
     }
 }
 
+#if !defined(WHOA_TEST_STORMDLL)
 TEST_CASE("SEvtDestroy", "[event]") {
     EventHandlerTest test;
 
@@ -117,6 +133,7 @@ TEST_CASE("SEvtDestroy", "[event]") {
         CHECK(SEvtDispatch(0, 0, 0, nullptr) == 1);
     }
 }
+#endif
 
 static void STORMAPI TestNestedDispatchEventHandler(void* data) {
     EventHandlerTest::RegisterCall(20, data);
diff --git a/test/EventTest.cpp b/test/EventTest.cpp
new file mode 100644
index 0000000..b76fa21
--- /dev/null
+++ b/test/EventTest.cpp
@@ -0,0 +1,29 @@
+#include "EventTest.hpp"
+
+std::deque<EventHandlerCalledWith> EventHandlerCallResults;
+
+
+void STORMAPI TestEventHandler1(void* data) {
+    EventHandlerTest::RegisterCall(1, data);
+}
+
+void STORMAPI TestEventHandler2(void* data) {
+    EventHandlerTest::RegisterCall(2, data);
+}
+
+void STORMAPI TestEventHandler3(void* data) {
+    EventHandlerTest::RegisterCall(3, data);
+}
+
+void STORMAPI TestEventHandler4(void* data) {
+    EventHandlerTest::RegisterCall(4, data);
+}
+
+std::ostream& operator <<(std::ostream& os, EventHandlerCalledWith const& value) {
+    os << "{ TestEventHandler" << value.handler << ", " << value.data << " }";
+    return os;
+}
+
+EventHandlerCalledWithMatcher<EventHandlerCalledWith> MatchesCall(EventHandlerCalledWith arg) {
+  return { arg };
+}
diff --git a/test/EventTest.hpp b/test/EventTest.hpp
index 45b5069..ec64c25 100644
--- a/test/EventTest.hpp
+++ b/test/EventTest.hpp
@@ -1,25 +1,22 @@
 #include "test/Test.hpp"
+#include "storm/Core.hpp"
 #include "storm/Event.hpp"
 
 #include <deque>
 #include <sstream>
 
 
-void SEvtCleanExtraDataForTests();
-
-
 struct EventHandlerCalledWith {
     int handler;
     void* data;
 };
 
-static std::deque<EventHandlerCalledWith> EventHandlerCallResults;
+extern std::deque<EventHandlerCalledWith> EventHandlerCallResults;
 
 struct EventHandlerTest {
     EventHandlerTest() {
         EventHandlerCallResults.clear();
-        SEvtDestroy();
-        SEvtCleanExtraDataForTests();
+        StormDestroy();
     }
 
     static void RegisterCall(int handler, void* data) {
@@ -43,28 +40,14 @@ struct EventHandlerTest {
 };
 
 
-static void STORMAPI TestEventHandler1(void* data) {
-    EventHandlerTest::RegisterCall(1, data);
-}
-
-static void STORMAPI TestEventHandler2(void* data) {
-    EventHandlerTest::RegisterCall(2, data);
-}
-
-static void STORMAPI TestEventHandler3(void* data) {
-    EventHandlerTest::RegisterCall(3, data);
-}
-
-static void STORMAPI TestEventHandler4(void* data) {
-    EventHandlerTest::RegisterCall(4, data);
-}
+void STORMAPI TestEventHandler1(void* data);
+void STORMAPI TestEventHandler2(void* data);
+void STORMAPI TestEventHandler3(void* data);
+void STORMAPI TestEventHandler4(void* data);
 
 
 // Helpers for comparing EventHandlerCalledWith structs
-std::ostream& operator <<(std::ostream& os, EventHandlerCalledWith const& value) {
-    os << "{ TestEventHandler" << value.handler << ", " << value.data << " }";
-    return os;
-}
+std::ostream& operator <<(std::ostream& os, EventHandlerCalledWith const& value);
 
 template <class T>
 class EventHandlerCalledWithMatcher : public Catch::MatcherBase<T> {
@@ -85,6 +68,4 @@ public:
   }
 };
 
-EventHandlerCalledWithMatcher<EventHandlerCalledWith> MatchesCall(EventHandlerCalledWith arg) {
-  return { arg };
-}
+EventHandlerCalledWithMatcher<EventHandlerCalledWith> MatchesCall(EventHandlerCalledWith arg);
diff --git a/test/Test.cpp b/test/Test.cpp
index fae4b8c..c5af3d8 100644
--- a/test/Test.cpp
+++ b/test/Test.cpp
@@ -1,6 +1,2 @@
-#define CATCH_CONFIG_MAIN
-#include "test/Test.hpp"
-#include "storm/Big.hpp"
-
-BigDataTest::BigDataTest() { SBigNew(&num); }
-BigDataTest::~BigDataTest() { SBigDel(num); }
+#define CATCH_CONFIG_MAIN
+#include "test/Test.hpp"
diff --git a/test/Test.hpp b/test/Test.hpp
index 990c842..da3dbbd 100644
--- a/test/Test.hpp
+++ b/test/Test.hpp
@@ -1,17 +1 @@
 #include "vendor/catch-2.13.10/catch.hpp"
-
-class BigData;
-
-// Fixture for repetitive handling of BigData objects.
-struct BigDataTest {
-    using BigDataPtr = BigData*;
-
-    BigData* num;
-
-    BigDataTest();
-    ~BigDataTest();
-
-    BigData** operator &() { return &num; }
-    operator BigDataPtr() const { return num; }
-    BigData* operator->() const { return num; }
-};
diff --git a/test/big/Ops.cpp b/test/big/Ops.cpp
index e2e7501..5a6a29c 100644
--- a/test/big/Ops.cpp
+++ b/test/big/Ops.cpp
@@ -1,6 +1,5 @@
-#include "storm/Big.hpp"
+#include "test/BigTest.hpp"
 #include "storm/big/Ops.hpp"
-#include "test/Test.hpp"
 #include <vector>
 
 TEST_CASE("Add", "[big]") {
diff --git a/test/stormdll/storm.def b/test/stormdll/storm.def
index f3744eb..45a6f4a 100644
--- a/test/stormdll/storm.def
+++ b/test/stormdll/storm.def
@@ -128,7 +128,7 @@ EXPORTS
 
     ; Main
     ; This is the only *Destroy function exported, tests will need to use it instead
-    ;StormDestroy                  @301 NONAME
+    StormDestroy                   @301 NONAME
     ;StormGetInstance              @302 NONAME
     ;StormGetOption                @303 NONAME
     ;StormSetOption                @304 NONAME
@@ -176,7 +176,7 @@ EXPORTS
     ;SDrawUpdatePalette            @357 NONAME
     ;SDrawUpdateScreen             @358 NONAME
     ;SDrawWaitForVerticalBlank     @359 NONAME
-    
+
     ; Event
     ;SEvtDestroy                   @371 NONAME
     SEvtDispatch                  @372 NONAME
diff --git a/test/stormdll/stormstubs.cpp b/test/stormdll/stormstubs.cpp
index 0c56037..feca531 100644
--- a/test/stormdll/stormstubs.cpp
+++ b/test/stormdll/stormstubs.cpp
@@ -1,3 +1,7 @@
+#include <storm/Core.hpp>
+
+int32_t STORMAPI StormDestroy() { return 0; }
+
 #include <storm/Big.hpp>
 
 void STORMAPI SBigAdd(BigData*, BigData*, BigData*) {}
@@ -40,7 +44,6 @@ void STORMAPI SErrSetLastError(uint32_t) {}
 uint32_t STORMAPI SErrGetLastError() { return 0; }
 void STORMAPI SErrSuppressErrors(uint32_t) {}
 
-
 #include <storm/Event.hpp>
 
 int32_t STORMAPI SEvtBreakHandlerChain(void*) { return 0; }