diff --git a/code/qcommon/common.c b/code/qcommon/common.c
index 092a2fd4f4..5b56bc2f47 100644
--- a/code/qcommon/common.c
+++ b/code/qcommon/common.c
@@ -2741,10 +2741,11 @@ void Com_Init( char *commandLine ) {
 	// init commands and vars
 	//
 	com_altivec = Cvar_Get ("com_altivec", "1", CVAR_ARCHIVE);
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 	// Under Emscripten the browser handles throttling the frame rate.
 	// Manual framerate throttling interacts poorly with Emscripten's
-	// browser-driven event loop. So default throttling to off.
+	// browser-driven event loop. So default throttling to off. See here
+	// for discussion: https://github.com/ioquake/ioq3/issues/675
 	com_maxfps = Cvar_Get ("com_maxfps", "0", CVAR_ARCHIVE);
 #else
 	com_maxfps = Cvar_Get ("com_maxfps", "85", CVAR_ARCHIVE);
diff --git a/code/renderergl2/tr_init.c b/code/renderergl2/tr_init.c
index 48da9ce3c6..20501eb540 100644
--- a/code/renderergl2/tr_init.c
+++ b/code/renderergl2/tr_init.c
@@ -1365,8 +1365,14 @@ void R_Register( void )
 	r_dlightBacks = ri.Cvar_Get( "r_dlightBacks", "1", CVAR_ARCHIVE );
 	r_finish = ri.Cvar_Get ("r_finish", "0", CVAR_ARCHIVE);
 	r_textureMode = ri.Cvar_Get( "r_textureMode", "GL_LINEAR_MIPMAP_LINEAR", CVAR_ARCHIVE );
-	r_swapInterval = ri.Cvar_Get( "r_swapInterval", "0",
-					CVAR_ARCHIVE | CVAR_LATCH );
+#ifdef __EMSCRIPTEN__
+	// Under Emscripten we don't throttle framerate with com_maxfps by default, so enable
+	// vsync by default instead. See here for discussion:
+	// https://github.com/ioquake/ioq3/issues/675
+	r_swapInterval = ri.Cvar_Get( "r_swapInterval", "1", CVAR_ARCHIVE | CVAR_LATCH );
+#else
+	r_swapInterval = ri.Cvar_Get( "r_swapInterval", "0", CVAR_ARCHIVE | CVAR_LATCH );
+#endif
 	r_gamma = ri.Cvar_Get( "r_gamma", "1", CVAR_ARCHIVE );
 	r_facePlaneCull = ri.Cvar_Get ("r_facePlaneCull", "1", CVAR_ARCHIVE );