diff --git a/runtime/syntax/c.yaml b/runtime/syntax/c.yaml
index 96dd04d2e..c517e507e 100644
--- a/runtime/syntax/c.yaml
+++ b/runtime/syntax/c.yaml
@@ -41,9 +41,9 @@ rules:
     - constant.string:
         start: "'"
         end: "'"
-        skip: "(\\\\.)|(.*[^']$)"
+        skip: "(\\\\.)|([^']{4}'[^']{4})"
         rules:
-            - error: "..+'"
+            - error: "[[:graph:]]{2,}"
             - constant.specialChar: "\\\\([\"'abfnrtv\\\\]|[0-3]?[0-7]{1,2}|x[0-9A-Fa-f]{1,2}|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})"
 
     - comment:
diff --git a/runtime/syntax/cpp.yaml b/runtime/syntax/cpp.yaml
index e2987ae1a..211725371 100644
--- a/runtime/syntax/cpp.yaml
+++ b/runtime/syntax/cpp.yaml
@@ -47,9 +47,9 @@ rules:
     - constant.string:
         start: "'"
         end: "'"
-        skip: "(\\\\.)|(.*[^']$)"
+        skip: "(\\\\.)|([^']{4}'[^']{4})"
         rules:
-            - error: "..+'"
+            - error: "[[:graph:]]{2,}"
             - constant.specialChar: "\\\\([\"'abfnrtv\\\\]|[0-3]?[0-7]{1,2}|x[0-9A-Fa-f]{1,2}|u[0-9A-Fa-f]{4}|U[0-9A-Fa-f]{8})"
 
     - comment: