diff --git a/src/engine.c b/src/engine.c
index cd1973b..4d2dcba 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -22,6 +22,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <sys/stat.h>
 #include <unistd.h>
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
 #ifdef __HAIKU__
 #include <FindDirectory.h>
 #elif !defined(_WIN32)
@@ -428,6 +432,43 @@ void engine_resetLists()
 	engine.debrisTail = engine.debrisHead;
 }
 
+/*
+Saves the config using current settings.
+*/
+void engine_saveConf()
+{
+	char filename[PATH_MAX];
+	FILE *fp;
+
+	snprintf(filename, PATH_MAX, "%sconf", engine.configDirectory);
+	fp = fopen(filename, "w");
+	if (fp != NULL)
+	{
+		fprintf(fp,
+			"%d %d %d %d %d\n"
+			"%s\n",
+			engine.fullScreen, engine.useSound, engine.useMusic,
+			engine.autoPause, engine.radioLife, engine.lang);
+		fclose(fp);
+	}
+	else
+	{
+		printf("Error saving config\n");
+	}
+}
+
+#ifdef __EMSCRIPTEN__
+/*
+Called by the web page when the tab is hidden or closed: the game only
+writes the config when it quits, which never happens in a browser tab.
+*/
+EMSCRIPTEN_KEEPALIVE void fredygames_save()
+{
+	if (strcmp(engine.configDirectory, "") != 0)
+		engine_saveConf();
+}
+#endif
+
 /*
 Removes [hopefully] all the resources that has been
 loaded and created during the game. This is called by
@@ -475,23 +516,7 @@ void engine_cleanup()
 	}
 #endif
 
-	// Save the config using current settings
-	FILE *fp;
-	snprintf(filename, PATH_MAX, "%sconf", engine.configDirectory);
-	fp = fopen(filename, "w");
-	if (fp != NULL)
-	{
-		fprintf(fp,
-			"%d %d %d %d %d\n"
-			"%s\n",
-			engine.fullScreen, engine.useSound, engine.useMusic,
-			engine.autoPause, engine.radioLife, engine.lang);
-		fclose(fp);
-	}
-	else
-	{
-		printf("Error saving config\n");
-	}
+	engine_saveConf();
 
 	SDL_Quit();
 	printf("Thank You for playing Starfighter\n");
diff --git a/src/engine.h b/src/engine.h
index 7836359..f165b71 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -119,6 +119,7 @@ void engine_setupConfigDirectory();
 void engine_setMode();
 void engine_setFullscreen(int value);
 void engine_resetLists();
+void engine_saveConf();
 void engine_cleanup();
 
 #endif
diff --git a/src/game.c b/src/game.c
index 8a06dcf..7132971 100644
--- a/src/game.c
+++ b/src/game.c
@@ -24,6 +24,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "SDL.h"
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
 #include "colors.h"
 #include "defs.h"
 #include "structs.h"
@@ -2390,7 +2394,14 @@ void game_delayFrame()
 	if(now < frameLimit)
 		SDL_Delay(frameLimit - now);
 	else
+	{
 		frameLimit = now;
+#ifdef __EMSCRIPTEN__
+		// Behind schedule: still give the browser its turn (SDL_Delay does
+		// that through Asyncify), or the page stops responding.
+		emscripten_sleep(0);
+#endif
+	}
 }
 
 /*