diff --git a/libgambatte/src/file/unzip/crypt.h b/libgambatte/src/file/unzip/crypt.h
index 7d8597c2..4141ae99 100644
--- a/libgambatte/src/file/unzip/crypt.h
+++ b/libgambatte/src/file/unzip/crypt.h
@@ -32,8 +32,9 @@
 /***********************************************************************
  * Return the next byte in the pseudo-random sequence
  */
-static int decrypt_byte(unsigned long* pkeys, const unsigned long* pcrc_32_tab __attribute__((unused)))
+static int decrypt_byte(unsigned long* pkeys, const unsigned long* pcrc_32_tab)
 {
+    (void)pcrc_32_tab;
     unsigned temp;  /* POTENTIAL BUG:  temp*(temp^1) may overflow in an
                      * unpredictable manner on 16-bit systems; not a problem
                      * with any known compiler so far, though */
diff --git a/libgambatte/src/file/unzip/ioapi.c b/libgambatte/src/file/unzip/ioapi.c
index 84795e34..3ada75e8 100644
--- a/libgambatte/src/file/unzip/ioapi.c
+++ b/libgambatte/src/file/unzip/ioapi.c
@@ -13,8 +13,6 @@
 #include <zlib.h>
 #include "ioapi.h"
 
-
-
 /* I've found an old Unix (a SunOS 4.1.3_U1) without all SEEK_* defined.... */
 
 #ifndef SEEK_CUR
@@ -65,11 +63,9 @@ int ZCALLBACK ferror_file_func OF((
    voidpf stream));
 
 
-voidpf ZCALLBACK fopen_file_func (opaque, filename, mode)
-   voidpf opaque __attribute__((unused));
-   const char* filename;
-   int mode;
+voidpf ZCALLBACK fopen_file_func (voidpf opaque, const char* filename, int mode)
 {
+    (void)opaque;
     FILE* file = NULL;
     const char* mode_fopen = NULL;
     if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER)==ZLIB_FILEFUNC_MODE_READ)
@@ -87,44 +83,34 @@ voidpf ZCALLBACK fopen_file_func (opaque, filename, mode)
 }
 
 
-uLong ZCALLBACK fread_file_func (opaque, stream, buf, size)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
-   void* buf;
-   uLong size;
+uLong ZCALLBACK fread_file_func (voidpf opaque, voidpf stream, void* buf, uLong size)
 {
+    (void)opaque;
     uLong ret;
     ret = (uLong)fread(buf, 1, (size_t)size, (FILE *)stream);
     return ret;
 }
 
 
-uLong ZCALLBACK fwrite_file_func (opaque, stream, buf, size)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
-   const void* buf;
-   uLong size;
+uLong ZCALLBACK fwrite_file_func (voidpf opaque, voidpf stream, const void* buf, uLong size)
 {
+    (void)opaque;
     uLong ret;
     ret = (uLong)fwrite(buf, 1, (size_t)size, (FILE *)stream);
     return ret;
 }
 
-long ZCALLBACK ftell_file_func (opaque, stream)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
+long ZCALLBACK ftell_file_func (voidpf opaque, voidpf stream)
 {
+    (void)opaque;
     long ret;
     ret = ftell((FILE *)stream);
     return ret;
 }
 
-long ZCALLBACK fseek_file_func (opaque, stream, offset, origin)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
-   uLong offset;
-   int origin;
+long ZCALLBACK fseek_file_func (voidpf opaque, voidpf stream, uLong offset, int origin)
 {
+    (void)opaque;
     int fseek_origin=0;
     long ret;
     switch (origin)
@@ -145,26 +131,23 @@ long ZCALLBACK fseek_file_func (opaque, stream, offset, origin)
     return ret;
 }
 
-int ZCALLBACK fclose_file_func (opaque, stream)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
+int ZCALLBACK fclose_file_func (voidpf opaque, voidpf stream)
 {
+    (void)opaque;
     int ret;
     ret = fclose((FILE *)stream);
     return ret;
 }
 
-int ZCALLBACK ferror_file_func (opaque, stream)
-   voidpf opaque __attribute__((unused));
-   voidpf stream;
+int ZCALLBACK ferror_file_func (voidpf opaque, voidpf stream)
 {
+    (void)opaque;
     int ret;
     ret = ferror((FILE *)stream);
     return ret;
 }
 
-void fill_fopen_filefunc (pzlib_filefunc_def)
-  zlib_filefunc_def* pzlib_filefunc_def;
+void fill_fopen_filefunc (zlib_filefunc_def* pzlib_filefunc_def)
 {
     pzlib_filefunc_def->zopen_file = fopen_file_func;
     pzlib_filefunc_def->zread_file = fread_file_func;
diff --git a/libgambatte/src/statesaver.cpp b/libgambatte/src/statesaver.cpp
index 501f5c42..78524fcb 100644
--- a/libgambatte/src/statesaver.cpp
+++ b/libgambatte/src/statesaver.cpp
@@ -23,6 +23,7 @@
 #include <algorithm>
 #include <fstream>
 #include <functional>
+#include <memory>
 #include <sstream>
 #include <vector>
 #include <cstring>
@@ -550,10 +551,10 @@ bool StateSaver::saveState(SaveState const &state,
 		return false;
 
 	std::size_t size = saveState(state, videoBuf, pitch, NULL, mode);
-	char stateBuf[size];
+	std::unique_ptr<char[]> stateBuf {new char[size]};
 
-	saveState(state, videoBuf, pitch, stateBuf, mode);
-	file.write(stateBuf, size);
+	saveState(state, videoBuf, pitch, stateBuf.get(), mode);
+	file.write(stateBuf.get(), size);
 
 	return !file.fail();
 }