diff --git a/CHANGES b/CHANGES
index 8bb66f6ed..409129e69 100644
--- a/CHANGES
+++ b/CHANGES
@@ -42,6 +42,7 @@ Bugfixes:
  - GBA BIOS: Fix ArcTan2 sign in HLE BIOS (fixes mgba.io/i/689)
  - GBA Video: Don't update background scanline params in mode 0 (fixes mgba.io/i/377)
  - Qt: Ensure CLI backend is attached when submitting commands (fixes mgba.io/i/662)
+ - Core: Fix crash with rewind if savestates shrink
 Misc:
  - SDL: Remove scancode key input
  - GBA Video: Clean up unused timers
diff --git a/src/core/rewind.c b/src/core/rewind.c
index 9919acf2e..53ee67188 100644
--- a/src/core/rewind.c
+++ b/src/core/rewind.c
@@ -50,6 +50,8 @@ void mCoreRewindAppend(struct mCoreRewindContext* context, struct mCore* core) {
 	if (size2 > size) {
 		context->currentState->truncate(context->currentState, size2);
 		size = size2;
+	} else if (size > size2) {
+		nextState->truncate(nextState, size);
 	}
 	void* current = context->currentState->map(context->currentState, size, MAP_READ);
 	void* next = nextState->map(nextState, size, MAP_READ);