diff --git a/port/include/system.h b/port/include/system.h
index 84d568382..dc581dfb9 100644
--- a/port/include/system.h
+++ b/port/include/system.h
@@ -32,6 +32,7 @@ void sysGetHomePath(char *outPath, const u32 outLen);
 
 void *sysMemAlloc(const u32 size);
 void *sysMemZeroAlloc(const u32 size);
+void *sysMemRealloc(void *ptr, const u32 newSize);
 void sysMemFree(void *ptr);
 
 // hns is specified in 100ns units
diff --git a/port/src/preprocess/filelang.c b/port/src/preprocess/filelang.c
index 841dbffe1..9869202fb 100644
--- a/port/src/preprocess/filelang.c
+++ b/port/src/preprocess/filelang.c
@@ -31,7 +31,7 @@ static int getNumStrings(u8 *src, size_t len)
 	return 1;
 }
 
-u32 convertLangFile(u8 *dst, u8 *src, size_t srclen)
+static u32 convertLangFile(u8 *dst, u8 *src, size_t srclen)
 {
 	// Convert it
 	u32 *src_offsets = (u32 *) src;
diff --git a/port/src/preprocess/segaudio.c b/port/src/preprocess/segaudio.c
index 56d7e3a13..3ddbdf5f3 100644
--- a/port/src/preprocess/segaudio.c
+++ b/port/src/preprocess/segaudio.c
@@ -316,11 +316,22 @@ static u32 convertAudioBankFile(u8 *dst, u8 *src)
 u8 *preprocessALBankFile(u8 *src, u32 size, u32 *outSize)
 {
 	ptrReset();
-	u32 dstlen = size * 3;
+
+	const u32 dstlen = size * 3; // this should overshoot any possible bank size, but * 2 also works for vanilla banks
 	u8 *dst = sysMemZeroAlloc(dstlen);
 
-	*outSize = convertAudioBankFile(dst, src);
-	*outSize = ALIGN16(*outSize);
+	u32 reallen = convertAudioBankFile(dst, src);
+	if (reallen > dstlen || ALIGN16(reallen) > dstlen) {
+		sysFatalError("overflow when trying to preprocess an ALBankFile, size %u dstlen %u reallen %u", size, dstlen, reallen);
+	}
+
+	reallen = ALIGN16(reallen);
+
+	if (reallen < dstlen) {
+		dst = sysMemRealloc(dst, reallen);
+	}
+
+	*outSize = reallen;
 
 	return dst;
 }
diff --git a/port/src/system.c b/port/src/system.c
index 16b689c47..60d94f592 100644
--- a/port/src/system.c
+++ b/port/src/system.c
@@ -288,6 +288,11 @@ void *sysMemZeroAlloc(const u32 size)
 	return calloc(1, size);
 }
 
+void *sysMemRealloc(void *ptr, const u32 newSize)
+{
+	return realloc(ptr, newSize);
+}
+
 void sysMemFree(void *ptr)
 {
 	free(ptr);