diff --git a/src/gba/gba.c b/src/gba/gba.c
index 568fb629e..2bef0c6a0 100644
--- a/src/gba/gba.c
+++ b/src/gba/gba.c
@@ -96,14 +96,22 @@ static void GBAInit(struct ARMCore* cpu, struct ARMComponent* component) {
 	gba->performingDMA = false;
 }
 
-void GBADestroy(struct GBA* gba) {
+void GBAUnloadROM(struct GBA* gba) {
 	if (gba->pristineRom == gba->memory.rom) {
 		gba->memory.rom = 0;
+	} else {
+		mappedMemoryFree(gba->pristineRom, gba->pristineRomSize);
 	}
 
 	if (gba->romVf) {
 		gba->romVf->unmap(gba->romVf, gba->pristineRom, gba->pristineRomSize);
+		gba->pristineRom = 0;
+		gba->romVf = 0;
 	}
+}
+
+void GBADestroy(struct GBA* gba) {
+	GBAUnloadROM(gba);
 
 	if (gba->biosVf) {
 		gba->biosVf->unmap(gba->biosVf, gba->memory.bios, SIZE_BIOS);
@@ -370,6 +378,7 @@ void GBADetachDebugger(struct GBA* gba) {
 }
 
 void GBALoadROM(struct GBA* gba, struct VFile* vf, struct VFile* sav, const char* fname) {
+	GBAUnloadROM(gba);
 	gba->romVf = vf;
 	gba->pristineRomSize = vf->size(vf);
 	vf->seek(vf, 0, SEEK_SET);
diff --git a/src/gba/gba.h b/src/gba/gba.h
index 636c2ae14..25212d19e 100644
--- a/src/gba/gba.h
+++ b/src/gba/gba.h
@@ -208,6 +208,7 @@ void GBAClearBreakpoint(struct GBA* gba, uint32_t address, enum ExecutionMode mo
 
 void GBALoadROM(struct GBA* gba, struct VFile* vf, struct VFile* sav, const char* fname);
 void GBAYankROM(struct GBA* gba);
+void GBAUnloadROM(struct GBA* gba);
 void GBALoadBIOS(struct GBA* gba, struct VFile* vf);
 void GBAApplyPatch(struct GBA* gba, struct Patch* patch);
 
diff --git a/src/gba/supervisor/thread.c b/src/gba/supervisor/thread.c
index b5a1fad42..8a39da3bb 100644
--- a/src/gba/supervisor/thread.c
+++ b/src/gba/supervisor/thread.c
@@ -23,6 +23,8 @@
 
 #include <signal.h>
 
+static void _loadGameDir(struct GBAThread* threadContext);
+
 static const float _defaultFPSTarget = 60.f;
 
 #ifndef DISABLE_THREADING
@@ -352,18 +354,7 @@ void GBAMapArgumentsToContext(const struct GBAArguments* args, struct GBAThread*
 		threadContext->gameDir = VDirOpen(args->fname);
 		threadContext->stateDir = threadContext->gameDir;
 	} else {
-		threadContext->rom = VFileOpen(args->fname, O_RDONLY);
-		threadContext->gameDir = 0;
-#if USE_LIBZIP
-		if (!threadContext->gameDir) {
-			threadContext->gameDir = VDirOpenZip(args->fname, 0);
-		}
-#endif
-#if USE_LZMA
-		if (!threadContext->gameDir) {
-			threadContext->gameDir = VDirOpen7z(args->fname, 0);
-		}
-#endif
+		GBAThreadLoadROM(threadContext, args->fname);
 	}
 	threadContext->fname = args->fname;
 	threadContext->patch = VFileOpen(args->patch, O_RDONLY);
@@ -398,25 +389,7 @@ bool GBAThreadStart(struct GBAThread* threadContext) {
 	}
 
 	if (threadContext->gameDir) {
-		threadContext->gameDir->rewind(threadContext->gameDir);
-		struct VDirEntry* dirent = threadContext->gameDir->listNext(threadContext->gameDir);
-		while (dirent) {
-			struct Patch patchTemp;
-			struct VFile* vf = threadContext->gameDir->openFile(threadContext->gameDir, dirent->name(dirent), O_RDONLY);
-			if (!vf) {
-				dirent = threadContext->gameDir->listNext(threadContext->gameDir);
-				continue;
-			}
-			if (!threadContext->rom && GBAIsROM(vf)) {
-				threadContext->rom = vf;
-			} else if (!threadContext->patch && loadPatch(vf, &patchTemp)) {
-				threadContext->patch = vf;
-			} else {
-				vf->close(vf);
-			}
-			dirent = threadContext->gameDir->listNext(threadContext->gameDir);
-		}
-
+		_loadGameDir(threadContext);
 	}
 
 	if (!threadContext->rom && !bootBios) {
@@ -678,6 +651,67 @@ void GBAThreadPauseFromThread(struct GBAThread* threadContext) {
 	GBASyncSetVideoSync(&threadContext->sync, frameOn);
 }
 
+void GBAThreadLoadROM(struct GBAThread* threadContext, const char* fname) {
+	threadContext->rom = VFileOpen(fname, O_RDONLY);
+	threadContext->gameDir = 0;
+#if USE_LIBZIP
+	if (!threadContext->gameDir) {
+		threadContext->gameDir = VDirOpenZip(fname, 0);
+	}
+#endif
+#if USE_LZMA
+	if (!threadContext->gameDir) {
+		threadContext->gameDir = VDirOpen7z(fname, 0);
+	}
+#endif
+}
+
+static void _loadGameDir(struct GBAThread* threadContext) {
+	threadContext->gameDir->rewind(threadContext->gameDir);
+	struct VDirEntry* dirent = threadContext->gameDir->listNext(threadContext->gameDir);
+	while (dirent) {
+		struct Patch patchTemp;
+		struct VFile* vf = threadContext->gameDir->openFile(threadContext->gameDir, dirent->name(dirent), O_RDONLY);
+		if (!vf) {
+			dirent = threadContext->gameDir->listNext(threadContext->gameDir);
+			continue;
+		}
+		if (!threadContext->rom && GBAIsROM(vf)) {
+			threadContext->rom = vf;
+		} else if (!threadContext->patch && loadPatch(vf, &patchTemp)) {
+			threadContext->patch = vf;
+		} else {
+			vf->close(vf);
+		}
+		dirent = threadContext->gameDir->listNext(threadContext->gameDir);
+	}
+}
+
+void GBAThreadReplaceROM(struct GBAThread* threadContext, const char* fname) {
+	GBAUnloadROM(threadContext->gba);
+
+	if (threadContext->rom) {
+		threadContext->rom->close(threadContext->rom);
+		threadContext->rom = 0;
+	}
+
+	if (threadContext->save) {
+		threadContext->save->close(threadContext->save);
+		threadContext->save = 0;
+	}
+
+	GBAThreadLoadROM(threadContext, fname);
+	if(threadContext->gameDir) {
+		_loadGameDir(threadContext);
+	}
+
+	threadContext->fname = fname;
+	threadContext->save = VDirOptionalOpenFile(threadContext->stateDir, threadContext->fname, "sram", ".sav", O_CREAT | O_RDWR);
+
+	GBARaiseIRQ(threadContext->gba, IRQ_GAMEPAK);
+	GBALoadROM(threadContext->gba, threadContext->rom, threadContext->save, threadContext->fname);
+}
+
 #ifdef USE_PTHREADS
 struct GBAThread* GBAThreadGetContext(void) {
 	pthread_once(&_contextOnce, _createTLS);
diff --git a/src/gba/supervisor/thread.h b/src/gba/supervisor/thread.h
index 8fc99b867..aa86940f2 100644
--- a/src/gba/supervisor/thread.h
+++ b/src/gba/supervisor/thread.h
@@ -126,6 +126,9 @@ void GBAThreadTogglePause(struct GBAThread* threadContext);
 void GBAThreadPauseFromThread(struct GBAThread* threadContext);
 struct GBAThread* GBAThreadGetContext(void);
 
+void GBAThreadLoadROM(struct GBAThread* threadContext, const char* fname);
+void GBAThreadReplaceROM(struct GBAThread* threadContext, const char* fname);
+
 #ifdef USE_PNG
 void GBAThreadTakeScreenshot(struct GBAThread* threadContext);
 #endif