diff --git a/gflib/malloc.c b/gflib/malloc.c
index dcfac6ee8..b3191e30b 100644
--- a/gflib/malloc.c
+++ b/gflib/malloc.c
@@ -1,5 +1,8 @@
 #include "global.h"
 #include "malloc.h"
+#if TESTING
+#include "test/test.h"
+#endif
 
 static void *sHeapStart;
 static u32 sHeapSize;
@@ -71,7 +74,27 @@ void *AllocInternal(void *heapStart, u32 size, const char *location)
         }
 
         if (pos->next == head)
+        {
+#if TESTING
+            const struct MemBlock *head = HeapHead();
+            const struct MemBlock *block = head;
+            do
+            {
+                if (block->allocated)
+                {
+                    const char *location = MemBlockLocation(block);
+                    if (location)
+                        MgbaPrintf_("%s: %d bytes allocated", location, block->size);
+                    else
+                        MgbaPrintf_("<unknown>: %d bytes allocated", block->size);
+                }
+                block = block->next;
+            }
+            while (block != head);
+            Test_ExitWithResult(TEST_RESULT_ERROR, "%s: OOM allocating %d bytes", location, size);
+#endif
             return NULL;
+        }
 
         pos = pos->next;
     }
diff --git a/include/fieldmap.h b/include/fieldmap.h
index 47072bd1b..ecb1e49c4 100644
--- a/include/fieldmap.h
+++ b/include/fieldmap.h
@@ -22,6 +22,7 @@
 #include "main.h"
 
 extern struct BackupMapLayout gBackupMapLayout;
+extern u16 ALIGNED(4) sBackupMapData[MAX_MAP_DATA_SIZE];
 
 u32 MapGridGetMetatileIdAt(int, int);
 u32 MapGridGetMetatileBehaviorAt(int, int);
diff --git a/include/test/battle.h b/include/test/battle.h
index ead67ce32..e77482e40 100644
--- a/include/test/battle.h
+++ b/include/test/battle.h
@@ -626,7 +626,7 @@ struct BattleTestRunnerState
 };
 
 extern const struct TestRunner gBattleTestRunner;
-extern struct BattleTestRunnerState *gBattleTestRunnerState;
+extern struct BattleTestRunnerState *const gBattleTestRunnerState;
 
 #define MEMBERS(...) VARARG_8(MEMBERS_, __VA_ARGS__)
 #define MEMBERS_0()
diff --git a/src/fieldmap.c b/src/fieldmap.c
index 0ece73c5c..8faab449a 100644
--- a/src/fieldmap.c
+++ b/src/fieldmap.c
@@ -25,7 +25,7 @@ struct ConnectionFlags
     u8 east:1;
 };
 
-EWRAM_DATA static u16 ALIGNED(4) sBackupMapData[MAX_MAP_DATA_SIZE] = {0};
+EWRAM_DATA u16 ALIGNED(4) sBackupMapData[MAX_MAP_DATA_SIZE] = {0};
 EWRAM_DATA struct MapHeader gMapHeader = {0};
 EWRAM_DATA struct Camera gCamera = {0};
 EWRAM_DATA static struct ConnectionFlags sMapConnectionFlags = {0};
diff --git a/test/test_runner_battle.c b/test/test_runner_battle.c
index 96ddd2f38..d8369850d 100644
--- a/test/test_runner_battle.c
+++ b/test/test_runner_battle.c
@@ -3,6 +3,7 @@
 #include "battle_anim.h"
 #include "battle_controllers.h"
 #include "characters.h"
+#include "fieldmap.h"
 #include "item_menu.h"
 #include "main.h"
 #include "malloc.h"
@@ -33,7 +34,9 @@
 #undef Q_4_12
 #define Q_4_12(n) (s32)((n) * 4096)
 
-EWRAM_DATA struct BattleTestRunnerState *gBattleTestRunnerState = NULL;
+// Alias sBackupMapData to avoid using heap.
+struct BattleTestRunnerState *const gBattleTestRunnerState = (void *)sBackupMapData;
+STATIC_ASSERT(sizeof(struct BattleTestRunnerState) <= sizeof(sBackupMapData), sBackupMapDataSpace);
 
 static void CB2_BattleTest_NextParameter(void);
 static void CB2_BattleTest_NextTrial(void);
@@ -122,9 +125,6 @@ static u32 BattleTest_EstimateCost(void *data)
 {
     u32 cost;
     const struct BattleTest *test = data;
-    STATE = AllocZeroed(sizeof(*STATE));
-    if (!STATE)
-        return 0;
     STATE->runRandomly = TRUE;
     InvokeTestFunction(test);
     cost = 1;
@@ -134,23 +134,21 @@ static u32 BattleTest_EstimateCost(void *data)
         cost *= 3;
     else if (STATE->trials > 1)
         cost *= STATE->trials;
-    FREE_AND_SET_NULL(STATE);
     return cost;
 }
 
 static void BattleTest_SetUp(void *data)
 {
     const struct BattleTest *test = data;
-    STATE = AllocZeroed(sizeof(*STATE));
-    if (!STATE)
-        Test_ExitWithResult(TEST_RESULT_ERROR, "OOM: STATE = AllocZerod(%d)", sizeof(*STATE));
+    memset(STATE, 0, sizeof(*STATE));
     InvokeTestFunction(test);
     STATE->parameters = STATE->parametersCount;
     if (STATE->parametersCount == 0 && test->resultsSize > 0)
         Test_ExitWithResult(TEST_RESULT_INVALID, "results without PARAMETRIZE");
-    STATE->results = AllocZeroed(test->resultsSize * STATE->parameters);
-    if (!STATE->results)
-        Test_ExitWithResult(TEST_RESULT_ERROR, "OOM: STATE->results = AllocZerod(%d)", sizeof(test->resultsSize * STATE->parameters));
+    if (sizeof(*STATE) + test->resultsSize * STATE->parameters > sizeof(sBackupMapData))
+        Test_ExitWithResult(TEST_RESULT_ERROR, "OOM: STATE (%d) + STATE->results (%d) too big for sBackupMapData (%d)", sizeof(*STATE), test->resultsSize * STATE->parameters, sizeof(sBackupMapData));
+    STATE->results = (void *)((char *)sBackupMapData + sizeof(struct BattleTestRunnerState));
+    memset(STATE->results, 0, test->resultsSize * STATE->parameters);
     switch (test->type)
     {
     case BATTLE_TEST_SINGLES:
@@ -962,15 +960,10 @@ static void CB2_BattleTest_NextTrial(void)
 
 static void BattleTest_TearDown(void *data)
 {
-    if (STATE)
-    {
-        // Free resources that aren't cleaned up when the battle was
-        // aborted unexpectedly.
-        if (STATE->tearDownBattle)
-            TearDownBattle();
-        FREE_AND_SET_NULL(STATE->results);
-        FREE_AND_SET_NULL(STATE);
-    }
+    // Free resources that aren't cleaned up when the battle was
+    // aborted unexpectedly.
+    if (STATE->tearDownBattle)
+        TearDownBattle();
 }
 
 static bool32 BattleTest_CheckProgress(void *data)
@@ -1843,8 +1836,6 @@ void QueueStatus(u32 sourceLine, struct BattlePokemon *battler, struct StatusEve
 void ValidateFinally(u32 sourceLine)
 {
     // Defer this error until after estimating the cost.
-    if (STATE->results == NULL)
-        return;
     INVALID_IF(STATE->parametersCount == 0, "FINALLY without PARAMETRIZE");
 }