diff --git a/runtime/syntax/nim.yaml b/runtime/syntax/nim.yaml
index 45f73d173b..71cc5b47d7 100644
--- a/runtime/syntax/nim.yaml
+++ b/runtime/syntax/nim.yaml
@@ -17,11 +17,42 @@ rules:
     - constant.number: "\\b0[ocC][0-7][0-7_]+\\b"
     - constant.number: "\\b0[bB][01][01_]+\\b"
     - constant.number: "\\b[0-9_]((\\.?)[0-9_]+)?[eE][+\\-][0-9][0-9_]+\\b"
-    - constant.string: "\"(\\\\.|[^\"])*\"|'(\\\\.|[^'])*'"
-    - comment: "[[:space:]]*(?:[^\\\\]|^)#.*$"
-    - comment:
-        start: "\\#\\["
-        end: "\\]\\#"
+    
+    - constant.string:
+        start: "\""
+        end: "(\"|$)"
+        skip: "\\\\."
+        rules:
+            - constant.specialChar: "\\\\([\"'abceflnprtv\\\\]|\\d+|x[0-9A-Fa-f]{2}|u[0-9A-Fa-f]{4}|u\\{[0-9A-Fa-f]+\\})"
+
+    - constant.string:
+        start: "(r|R)\""
+        end: "(\"|$)"
+        skip: "\\\\."
+        rules: []
+
+    - constant.string:
+        start: "\"\"\""
+        end: "\"\"\""
+        skip: "\\\\."
         rules: []
 
-    - todo: "(TODO|FIXME|XXX):?"
+    - constant.string:
+        start: "'"
+        end: "('|$)"
+        skip: "\\\\."
+        rules:
+            - error: "[[:graph:]]{2,}'"
+            - constant.specialChar: "\\\\([\"'abceflnprtv\\\\]|\\d+|x[0-9A-Fa-f]{2}|u[0-9A-Fa-f]{4}|u\\{[0-9A-Fa-f]+\\})"
+
+    - comment:
+        start: "#\\["
+        end: "\\]#"
+        rules:
+            - todo: "(TODO|FIXME|XXX):?"
+
+    - comment:
+        start: "#"
+        end: "$"
+        rules:
+            - todo: "(TODO|FIXME|XXX):?"