diff --git a/src/common.h b/src/common.h
index 84ad8ed..ef9b0aa 100644
--- a/src/common.h
+++ b/src/common.h
@@ -9,8 +9,8 @@
 
 #define SYSTEM3_VERSION "1.6.1"
 
-#include <SDL.h>
 #include <limits.h>
+#include <stdint.h>
 #include <stdio.h>
 
 #ifdef __EMSCRIPTEN__
@@ -50,6 +50,7 @@ enum CustomEvent {
 };
 
 // resource.cpp
+struct SDL_RWops;
 SDL_RWops* open_resource(const char* name, const char* type);
 SDL_RWops* open_file(const char* name);
 
diff --git a/src/emscripten/mako.cpp b/src/emscripten/mako.cpp
index a91a28c..ab83857 100644
--- a/src/emscripten/mako.cpp
+++ b/src/emscripten/mako.cpp
@@ -4,6 +4,7 @@
 */
 
 #include <memory>
+#include <SDL.h>
 #include <emscripten.h>
 #include "mako.h"
 #include "fm/mako_ymfm.h"
diff --git a/src/resource.cpp b/src/resource.cpp
index 6f71ecd..100a711 100644
--- a/src/resource.cpp
+++ b/src/resource.cpp
@@ -4,6 +4,7 @@
 #undef min
 #undef max
 #endif
+#include <SDL.h>
 #include "common.h"
 
 SDL_RWops* open_resource(const char* name, const char* type) {
diff --git a/src/sys/dri.cpp b/src/sys/dri.cpp
index e62cb0a..46e09b0 100644
--- a/src/sys/dri.cpp
+++ b/src/sys/dri.cpp
@@ -7,6 +7,7 @@
 #include "dri.h"
 #include <memory>
 #include <string.h>
+#include <SDL.h>
 #include "game_id.h"
 #include "fileio.h"
 
diff --git a/src/sys/game_id.cpp b/src/sys/game_id.cpp
index 1cf3602..3cf6dee 100644
--- a/src/sys/game_id.cpp
+++ b/src/sys/game_id.cpp
@@ -1,4 +1,5 @@
 #include <string.h>
+#include <SDL.h>
 #include "game_id.h"
 #include "fileio.h"
 #include "config.h"
diff --git a/src/sys/nact.h b/src/sys/nact.h
index 34d10d8..d5bf4ef 100644
--- a/src/sys/nact.h
+++ b/src/sys/nact.h
@@ -11,6 +11,7 @@
 #include <string>
 #include <vector>
 #include <stdio.h>
+#include <SDL.h>
 #include "common.h"
 #include "config.h"
 #include "dri.h"