diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 1cd6a134e..43c719a43 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -478,8 +478,10 @@ Note: Future revisions to the HUD API may be incompatible; the HUD API is still
 
 - image
     Displays an image on the HUD.
-	- scale: The scale of the image, with 1 being the original texture size.
-             Only the X coordinate scale is used.
+    - scale: The scale of the image, with 1 being the original texture size.
+             Only the X coordinate scale is used (positive values)
+             Negative values represent that percentage of the screen it
+             should take; e.g. x=-100 means 100% (width)
     - text: The name of the texture that is displayed.
     - alignment: The alignment of the image.
     - offset: offset in pixels from position.
diff --git a/src/hud.cpp b/src/hud.cpp
index a0086b2f7..183f94e49 100644
--- a/src/hud.cpp
+++ b/src/hud.cpp
@@ -234,13 +234,16 @@ void Hud::drawLuaElements() {
 				const video::SColor color(255, 255, 255, 255);
 				const video::SColor colors[] = {color, color, color, color};
 				core::dimension2di imgsize(texture->getOriginalSize());
-				core::rect<s32> rect(0, 0, imgsize.Width  * e->scale.X,
-									       imgsize.Height * e->scale.X);
-				rect += pos;
-				v2s32 offset((e->align.X - 1.0) * ((imgsize.Width  * e->scale.X) / 2),
-				             (e->align.Y - 1.0) * ((imgsize.Height * e->scale.X) / 2));
-				rect += offset;
-				rect += v2s32(e->offset.X, e->offset.Y);
+				v2s32 dstsize(imgsize.Width * e->scale.X,
+				              imgsize.Height * e->scale.Y);
+				if (e->scale.X < 0)
+					dstsize.X = screensize.X * (e->scale.X * -0.01);
+				if (e->scale.Y < 0)
+					dstsize.Y = screensize.Y * (e->scale.Y * -0.01);
+				v2s32 offset((e->align.X - 1.0) * dstsize.X / 2,
+				             (e->align.Y - 1.0) * dstsize.Y / 2);
+				core::rect<s32> rect(0, 0, dstsize.X, dstsize.Y);
+				rect += pos + offset + v2s32(e->offset.X, e->offset.Y);
 				driver->draw2DImage(texture, rect,
 					core::rect<s32>(core::position2d<s32>(0,0), imgsize),
 					NULL, colors, true);
diff --git a/src/map.cpp b/src/map.cpp
index 55b758055..e8115d39b 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -3935,8 +3935,10 @@ s16 ServerMap::updateBlockHeat(ServerEnvironment *env, v3s16 p, MapBlock *block)
 	f32 heat = m_emerge->biomedef->calcBlockHeat(p, m_seed,
 			env->getTimeOfDayF(), gametime * env->getTimeOfDaySpeed());
 
-	block->heat = heat;
-	block->weather_update_time = gametime;
+	if(block) {
+		block->heat = heat;
+		block->weather_update_time = gametime;
+	}
 	return heat;
 }
 
@@ -3954,8 +3956,10 @@ s16 ServerMap::updateBlockHumidity(ServerEnvironment *env, v3s16 p, MapBlock *bl
 	f32 humidity = m_emerge->biomedef->calcBlockHumidity(p, m_seed,
 			env->getTimeOfDayF(), gametime * env->getTimeOfDaySpeed());
 			
-	block->humidity = humidity;
-	block->weather_update_time = gametime;
+	if(block) {
+		block->humidity = humidity;
+		block->weather_update_time = gametime;
+	}
 	return humidity;
 }