diff --git a/include/global.h b/include/global.h
index 89f7251767..60476b13f1 100644
--- a/include/global.h
+++ b/include/global.h
@@ -135,6 +135,10 @@
 #define NUM_FLAG_BYTES ROUND_BITS_TO_BYTES(FLAGS_COUNT)
 #define NUM_ADDITIONAL_PHRASE_BYTES ROUND_BITS_TO_BYTES(NUM_ADDITIONAL_PHRASES)
 
+// This produces an error at compile-time if expr is zero.
+// It looks like file.c:line: size of array `id' is negative
+#define STATIC_ASSERT(expr, id) typedef char id[(expr) ? 1 : -1];
+
 struct Coords8
 {
     s8 x;
diff --git a/src/ereader_helpers.c b/src/ereader_helpers.c
index ac6e0e1e1c..cf3ca16c31 100755
--- a/src/ereader_helpers.c
+++ b/src/ereader_helpers.c
@@ -15,6 +15,8 @@
 #include "constants/items.h"
 #include "constants/trainer_hill.h"
 
+STATIC_ASSERT(sizeof(struct TrainerHillChallenge) <= SECTOR_DATA_SIZE, TrainerHillChallengeFreeSpace);
+
 struct SendRecvMgr
 {
     bool8 isParent;
diff --git a/src/hall_of_fame.c b/src/hall_of_fame.c
index d134f22654..fe19ae77b0 100644
--- a/src/hall_of_fame.c
+++ b/src/hall_of_fame.c
@@ -52,6 +52,8 @@ struct HallofFameTeam
     struct HallofFameMon mon[PARTY_SIZE];
 };
 
+STATIC_ASSERT(sizeof(struct HallofFameTeam) * HALL_OF_FAME_MAX_TEAMS <= SECTOR_DATA_SIZE * NUM_HOF_SECTORS, HallOfFameFreeSpace);
+
 struct HofGfx
 {
     u16 state;
diff --git a/src/recorded_battle.c b/src/recorded_battle.c
index fd2b3a06b3..951572636a 100644
--- a/src/recorded_battle.c
+++ b/src/recorded_battle.c
@@ -67,6 +67,8 @@ struct RecordedBattleSave
     u32 checksum;
 };
 
+STATIC_ASSERT(sizeof(struct RecordedBattleSave) <= SECTOR_DATA_SIZE, RecordedBattleSaveFreeSpace);
+
 EWRAM_DATA u32 gRecordedBattleRngSeed = 0;
 EWRAM_DATA u32 gBattlePalaceMoveSelectionRngValue = 0;
 EWRAM_DATA static u8 sBattleRecords[MAX_BATTLERS_COUNT][BATTLER_RECORD_SIZE] = {0};
diff --git a/src/save.c b/src/save.c
index dafc20868e..52cdaa5ddc 100644
--- a/src/save.c
+++ b/src/save.c
@@ -73,6 +73,12 @@ struct
     SAVEBLOCK_CHUNK(struct PokemonStorage, 8), // SECTOR_ID_PKMN_STORAGE_END
 };
 
+// These will produce an error if a save struct is larger than the space
+// alloted for it in the flash.
+STATIC_ASSERT(sizeof(struct SaveBlock2) <= SECTOR_DATA_SIZE, SaveBlock2FreeSpace);
+STATIC_ASSERT(sizeof(struct SaveBlock1) <= SECTOR_DATA_SIZE * (SECTOR_ID_SAVEBLOCK1_END - SECTOR_ID_SAVEBLOCK1_START + 1), SaveBlock1FreeSpace);
+STATIC_ASSERT(sizeof(struct PokemonStorage) <= SECTOR_DATA_SIZE * (SECTOR_ID_PKMN_STORAGE_END - SECTOR_ID_PKMN_STORAGE_START + 1), PokemonStorageFreeSpace);
+
 u16 gLastWrittenSector;
 u32 gLastSaveCounter;
 u16 gLastKnownGoodSector;