diff --git a/build/image-optimization.sh b/build/image-optimization.sh
index a1be5d22ce1..81866a0fee4 100755
--- a/build/image-optimization.sh
+++ b/build/image-optimization.sh
@@ -1,20 +1,64 @@
 #!/usr/bin/env bash
 
+CHECK_DIR='../'
+if ! [ "$SERVER_VERSION" ]; then
+	CHECK_DIR=$1
+fi
+
 function recursive_optimize_images() {
-cd $1;
-optipng -o6 -strip all *.png;
-jpegoptim --strip-all *.jpg;
-for svg in `ls *.svg`;
-do
-    mv $svg $svg.opttmp;
-    scour --create-groups --enable-id-stripping --enable-comment-stripping --shorten-ids --remove-metadata --strip-xml-prolog --no-line-breaks  -i $svg.opttmp -o $svg;
-done;
-rm *.opttmp
-for dir in `ls -d */`;
-do
-    recursive_optimize_images $dir;
-    cd ..;
-done;
+	cd "$1" || return
+	DIR_NAME=${PWD##*/}
+
+	if [[ "$DIR_NAME" == "node_modules" ]]; then
+		return
+	elif [[ "$DIR_NAME" == "tests" ]]; then
+		return
+	fi
+
+	# Optimize all PNGs
+	for png in *.png
+	do
+		[[ -e "$png" ]] || break
+
+		optipng -o6 -strip all "$png"
+	done
+
+	# Optimize all JPGs
+	for jpg in *.jpg
+	do
+		[[ -e "$jpg" ]] || break
+
+		jpegoptim --strip-all "$jpg"
+	done
+
+	# Optimize all SVGs
+	for svg in *.svg
+	do
+		[[ -e "$svg" ]] || break
+
+		mv $svg $svg.opttmp
+		scour --create-groups \
+			--enable-id-stripping \
+			--enable-comment-stripping \
+			--shorten-ids \
+			--remove-metadata \
+			--strip-xml-prolog \
+			--no-line-breaks  \
+			-i $svg.opttmp \
+			-o $svg
+		rm $svg.opttmp
+	done
+
+	# Check all subfolders
+	for dir in */
+	do
+		[[ -e "$dir" ]] || break
+
+		if [[ -d "$dir" ]]; then
+			recursive_optimize_images "$dir"
+			cd ..
+		fi
+	done
 }
 
-recursive_optimize_images ../
+recursive_optimize_images "$CHECK_DIR"