diff --git a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
--- a/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
+++ b/clang-tools-extra/clang-tidy/readability/IdentifierNamingCheck.cpp
@@ -472,7 +472,7 @@
     Buffer.append(CStr.first);
     StringRef Val = Options.get(Buffer, "");
     if (!Val.empty())
-      HNOption.CString[CStr.first] = Val.str();
+      HNOption.CString[CStr.second] = Val.str();
   }
 
   Buffer = {Section, "PrimitiveType."};
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -169,6 +169,10 @@
   <clang-tidy/checks/misc/unused-using-decls>` check.
   Global options of the same name should be used instead.
 
+- Fixed reading `HungarianNotation.CString.*` options in
+  :doc:`readability-identifier-naming
+  <clang-tidy/checks/readability/identifier-naming>` check.
+
 Removed checks
 ^^^^^^^^^^^^^^