diff --git a/Quake/glquake.h b/Quake/glquake.h
index f1d2bf36..5f49bb2d 100644
--- a/Quake/glquake.h
+++ b/Quake/glquake.h
@@ -286,7 +286,7 @@ int R_LightPoint (vec3_t p);
 void GL_SubdivideSurface (msurface_t *fa);
 void R_BuildLightMap (msurface_t *surf, byte *dest, int stride);
 void R_RenderDynamicLightmaps (msurface_t *fa);
-void R_UploadLightmap (int lmap);
+void R_UploadLightmaps ();
 
 void R_DrawTextureChains_ShowTris (void);
 void R_DrawBrushModel_ShowTris (entity_t *e);
diff --git a/Quake/r_brush.c b/Quake/r_brush.c
index a78b287d..4805e066 100644
--- a/Quake/r_brush.c
+++ b/Quake/r_brush.c
@@ -207,7 +207,6 @@ void R_DrawSequentialPoly (msurface_t *s)
 
 		R_RenderDynamicLightmaps (s);
 		GL_Bind (lightmap_textures[s->lightmaptexturenum]);
-		R_UploadLightmap(s->lightmaptexturenum);
 		if (!gl_overbright.value)
 		{
 			glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
@@ -317,7 +316,6 @@ void R_DrawSequentialPoly (msurface_t *s)
 			GL_EnableMultitexture(); // selects TEXTURE1
 			GL_Bind (lightmap_textures[s->lightmaptexturenum]);
 			R_RenderDynamicLightmaps (s);
-			R_UploadLightmap(s->lightmaptexturenum);
 			glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);
 			glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_EXT, GL_MODULATE);
 			glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB_EXT, GL_PREVIOUS_EXT);
@@ -355,7 +353,6 @@ void R_DrawSequentialPoly (msurface_t *s)
 			//second pass -- lightmap with black fog, modulate blended
 			R_RenderDynamicLightmaps (s);
 			GL_Bind (lightmap_textures[s->lightmaptexturenum]);
-			R_UploadLightmap(s->lightmaptexturenum);
 			glDepthMask (GL_FALSE);
 			glEnable (GL_BLEND);
 			glBlendFunc(GL_DST_COLOR, GL_SRC_COLOR); //2x modulate
@@ -398,7 +395,6 @@ void R_DrawSequentialPoly (msurface_t *s)
 			GL_EnableMultitexture(); // selects TEXTURE1
 			GL_Bind (lightmap_textures[s->lightmaptexturenum]);
 			R_RenderDynamicLightmaps (s);
-			R_UploadLightmap(s->lightmaptexturenum);
 			glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 			glBegin(GL_POLYGON);
 			v = s->polys->verts[0];
@@ -430,7 +426,6 @@ void R_DrawSequentialPoly (msurface_t *s)
 			//second pass -- lightmap with black fog, modulate blended
 			R_RenderDynamicLightmaps (s);
 			GL_Bind (lightmap_textures[s->lightmaptexturenum]);
-			R_UploadLightmap(s->lightmaptexturenum);
 			glDepthMask (GL_FALSE);
 			glEnable (GL_BLEND);
 			glBlendFunc (GL_ZERO, GL_SRC_COLOR); //modulate
@@ -1150,7 +1145,7 @@ R_UploadLightmap -- johnfitz -- uploads the modified lightmap to opengl if neces
 assumes lightmap texture is already bound
 ===============
 */
-void R_UploadLightmap(int lmap)
+static void R_UploadLightmap(int lmap)
 {
 	glRect_t	*theRect;
 
@@ -1170,6 +1165,20 @@ void R_UploadLightmap(int lmap)
 	rs_dynamiclightmaps++;
 }
 
+void R_UploadLightmaps (void)
+{
+	int lmap;
+
+	for (lmap = 0; lmap < MAX_LIGHTMAPS; lmap++)
+	{
+		if (!lightmap_modified[lmap])
+			continue;
+
+		GL_Bind (lightmap_textures[lmap]);
+		R_UploadLightmap(lmap);
+	}
+}
+
 /*
 ================
 R_RebuildAllLightmaps -- johnfitz -- called when gl_overbright gets toggled
diff --git a/Quake/r_world.c b/Quake/r_world.c
index 9b880ba9..377ed568 100644
--- a/Quake/r_world.c
+++ b/Quake/r_world.c
@@ -373,7 +373,6 @@ void R_DrawTextureChains_Multitexture (void)
 				}
 				R_RenderDynamicLightmaps (s);
 				GL_Bind (lightmap_textures[s->lightmaptexturenum]);
-				R_UploadLightmap(s->lightmaptexturenum);
 				glBegin(GL_POLYGON);
 				v = s->polys->verts[0];
 				for (j=0 ; j<s->polys->numverts ; j++, v+= VERTEXSIZE)
@@ -587,7 +586,6 @@ void R_DrawLightmapChains (void)
 			continue;
 
 		GL_Bind (lightmap_textures[i]);
-		R_UploadLightmap(i);
 		for (p = lightmap_polys[i]; p; p=p->chain)
 		{
 			glBegin (GL_POLYGON);
@@ -613,6 +611,10 @@ void R_DrawWorld (void)
 	if (!r_drawworld_cheatsafe)
 		return;
 
+// mh dynamic lightmap speedup: upload all modified lightmaps from the last
+// frame in a single batch
+	R_UploadLightmaps ();
+	
 	if (r_drawflat_cheatsafe)
 	{
 		glDisable (GL_TEXTURE_2D);