diff --git a/include/yaz0.h b/include/yaz0.h
index 1efb5ac3cf..7f05fb293e 100644
--- a/include/yaz0.h
+++ b/include/yaz0.h
@@ -5,6 +5,8 @@
 
 void Yaz0_Decompress(uintptr_t romStart, void* dst, size_t size);
 
+#if MM_VERSION >= N64_US
 extern void* gYaz0DecompressDstEnd;
+#endif
 
 #endif
diff --git a/src/boot/yaz0.c b/src/boot/yaz0.c
index 16d8d32458..82d7016223 100644
--- a/src/boot/yaz0.c
+++ b/src/boot/yaz0.c
@@ -11,7 +11,9 @@ uintptr_t sYaz0CurRomStart;
 size_t sYaz0CurSize;
 u8* sYaz0MaxPtr;
 
+#if MM_VERSION >= N64_US
 void* gYaz0DecompressDstEnd;
+#endif
 
 #include "yaz0.h"
 
@@ -83,6 +85,9 @@ s32 Yaz0_DecompressImpl(u8* src, u8* dst) {
     u32 magic = ((Yaz0Header*)src)->magic;
 
     if (magic != YAZ0_MAGIC) {
+        PRINTF(T("slidstart_szs IDが違います (%02x %02x %02x %02x %08x)\n",
+                 "The slidstart_szs ID is incorrect (%02x %02x %02x %02x %08x)\n"),
+               src[0], src[1], src[2], src[3], magic);
         return -1;
     }
 
@@ -123,7 +128,9 @@ s32 Yaz0_DecompressImpl(u8* src, u8* dst) {
         bitIndex--;
     } while (dst != dstEnd);
 
+#if MM_VERSION >= N64_US
     gYaz0DecompressDstEnd = dstEnd;
+#endif
 
     return 0;
 }
diff --git a/src/code/sys_cmpdma.c b/src/code/sys_cmpdma.c
index adf41de49e..ad94ced93d 100644
--- a/src/code/sys_cmpdma.c
+++ b/src/code/sys_cmpdma.c
@@ -2,6 +2,7 @@
 
 #include "libc64/malloc.h"
 #include "color.h"
+#include "versions.h"
 #include "yaz0.h"
 #include "z64dma.h"
 
@@ -116,6 +117,8 @@ void CmpDma_LoadAllFiles(uintptr_t segmentVrom, void* dst, size_t size) {
 
     for (i = 0; i < end; i++) {
         CmpDma_LoadFileImpl(rom, i, nextDst, 0);
+#if MM_VERSION >= N64_US
         nextDst = gYaz0DecompressDstEnd;
+#endif
     }
 }