diff --git a/.github/workflows/whitespace_checks.yml b/.github/workflows/whitespace_checks.yml
index cc16e7b22..7f6f615cc 100644
--- a/.github/workflows/whitespace_checks.yml
+++ b/.github/workflows/whitespace_checks.yml
@@ -14,6 +14,7 @@ on:
       - '**.sh'
       - '**.cmake'
       - '**.glsl'
+      - '**.lua'
   pull_request:
     paths:
       - '**.txt'
@@ -24,6 +25,7 @@ on:
       - '**.sh'
       - '**.cmake'
       - '**.glsl'
+      - '**.lua'
 
 jobs:
   trailing_whitespaces:
@@ -34,6 +36,32 @@ jobs:
       - name: Check trailing whitespaces
         run: if git ls-files | grep -E '\.txt$|\.md$|\.[ch]$|\.cpp$|\.hpp$|\.sh$|\.cmake$|\.glsl$' | xargs grep -n '\s$'; then echo -e "\033[0;31mFound trailing whitespace"; (exit 1); else (exit 0); fi
 
+  indent_spaces:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      # Line endings are already ensured by .gitattributes
+      # Multiple multline comments in one line is not supported by this check 
+      # and there is no reason to use them
+      # So lines like: "/* */ /*" or "*/ a = 5; /*" will result in error
+      - name: Check for unsupported multiline comments
+        run: |
+          if git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$' | xargs grep -n '\*/.*/\*'; then echo -e "\033[0;31mUnsupported combination of multiline comments. New multiline comment should begin on new line."; (exit 1); else (exit 0); fi
+          if git ls-files | grep -E '\.lua$' | xargs grep -n -e '\]\].*--\[\['; then echo -e "\033[0;31mUnsupported combination of multiline comments. New multiline comment should begin on new line."; (exit 1); else (exit 0); fi
+      # This prepare files for final check 
+      # See python script ./util/ci/indent_tab_preprocess.py for details.
+      - name: Preprocess files
+        run: |
+          git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$' | xargs -L 1 -P $(($(nproc) + 1)) python3 ./util/ci/indent_tab_preprocess.py "/*" "*/"
+          git ls-files | grep -E '\.lua$' | xargs -L 1 -P $(($(nproc) + 1))  python3 ./util/ci/indent_tab_preprocess.py "--[[" "]]"
+      # Check for bad indent.
+      # This runs over preprocessed files.
+      # If there is any remaining space on line beginning or after tab,
+      # error is generated
+      - name: Check indent spaces
+        run: |
+          if git ls-files | grep -E '^src/.*\.cpp$|^src/.*\.[ch]$|\.lua' | xargs grep -n -P '^\t*[ ]'; then echo -e "\033[0;31mFound incorrect indent whitespaces"; (exit 1); else (exit 0); fi
+
   tabs_lua_api_files:
     runs-on: ubuntu-latest
     steps:
diff --git a/util/ci/indent_tab_preprocess.py b/util/ci/indent_tab_preprocess.py
new file mode 100644
index 000000000..50d7f7686
--- /dev/null
+++ b/util/ci/indent_tab_preprocess.py
@@ -0,0 +1,152 @@
+#!/usr/bin/python3
+
+import sys
+import re
+
+# preprocess files for indent check
+
+# Code processing:
+#
+# Tabs are kept.
+# Spaces after tabs are removed if indent is not smaller than in previous line.
+#
+# Example:
+#
+# <tab>a = 6;
+# <spc>b = 5;
+# <tab><spc>if (
+# <tab><tab><tab><spc><spc>) {
+# <tab><tab>c = 7;
+# <tab><spc>}
+#
+# Result:
+#
+# <tab>a = 6;
+# <spc>b = 5;
+# <tab>if (
+# <tab><tab><tab>) {
+# <tab><tab>c = 7;
+# <tab><spc>}
+
+# Multiline comments processing:
+#
+# It is expected that tabs indent from comment begining is
+# used as indent on begining of every commented line.
+#
+# Example:
+#
+# <tab>/*
+# <spc><spc>A
+# <tab><tab>B
+# <tab><spc>C
+# D
+# <tab><spc>*/
+# <tab><tab>/*
+# <spc><tab><spc>R
+#	<tab><spc><tab>*/
+#
+# Result:
+#
+# <tab>/*
+# <spc>A
+# <tab>B
+# <tab>C
+# D
+# <tab>*/
+# <tab><tab>/*
+# <spc><tab>*R
+#	<tab><spc>*/
+
+
+def main():
+	if len(sys.argv) != 4:
+		#print("Bad arguments")
+		#print(sys.argv)
+		exit()
+	# multiline comment begining and end from command line
+	mlc_begin = sys.argv[1]
+	mlc_end = sys.argv[2]
+	file_name = sys.argv[3]
+
+	mlc_end_len = len(mlc_end)
+	re_begin = re.escape(mlc_begin)
+	re_end = re.escape(mlc_end)
+
+	re_mlc_begin = "^.*{}".format(re_begin)
+	re_mlc_begin_end = "^.*{}.*{}".format(re_begin, re_end)
+	re_mlc_end = "^.*{}".format(re_end)
+
+	file = open(file_name, "r")
+
+	lines = []
+
+	#print(re_mlc_begin)
+	#print(re_mlc_begin_end)
+	#print(re_mlc_end)
+	#print(file)
+
+	# -1 means not in the multiline comment
+	# other values mean multiline comment indent in the number of tabs
+	limit = -1
+	# this value stores the previous line indent in code mode (not in multiline comment)
+	prev = 80
+	for line in file:
+		if limit == -1:
+			find = re.search(re_mlc_begin, line)
+			if find:
+				if not re.search(re_mlc_begin_end, line):
+					# enter in block comment mode
+					find = re.search("^\\s*", line)
+					limit = find.end()
+			find = re.search("^\\t*", line)
+			end = find.end()
+			if end < prev:
+				lines.append(line)
+			else:
+				# in this case, there can be allowed extra trailing whitespaces
+				# up to 3 trailing whitespaces are allowed
+				#find = re.search("^\\t+[ ]{0,3}", line)
+				# unlimited number of trailng whitespaces are allowed
+				find = re.search("^\\t+[ ]*", line)
+				fend = find.end() if find else 0
+				if fend >= end:
+					find = re.search("^\\t*", line)
+					lines.append(line[0:find.end()] + line[fend:])
+				else:
+					lines.append(line)
+			prev = end
+		else:
+			# in block comment mode
+			find = re.search(re_mlc_end, line)
+			if find:
+				# erase whitechars enabled for ignore, end in block comment mode
+				begin = find.end() - mlc_end_len
+				if begin > limit:
+					lines.append(line[0:limit] + line[begin:])
+				else:
+					lines.append(line)
+				limit = -1
+			else:
+				# erase whitechars enabled for ignore
+				find = re.search("^$", line)
+				if find:
+					lines.append(line)
+				else:
+					find = re.search("^\\s*", line)
+					if find:
+						end = find.end()
+						if end > limit:
+							lines.append(line[0:limit] + line[end:])
+						else:
+							lines.append(line)
+					else:
+						lines.append(line)
+
+	file.close()
+	file = open(file_name, "w")
+	for line in lines:
+		file.write(line)
+	file.close()
+
+if __name__ == "__main__":
+	main()