diff --git a/change_notes/2024-02-12-improve-a18-0-1.md b/change_notes/2024-02-12-improve-a18-0-1.md
new file mode 100644
index 0000000000..a4a9613a45
--- /dev/null
+++ b/change_notes/2024-02-12-improve-a18-0-1.md
@@ -0,0 +1,2 @@
+- `A18-0-1` - `CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.ql`:
+    - Fix issue #7 - improve query logic to only match on exact standard library names (e.g., now excludes sys/header.h type headers from the results as those are not C standard libraries).
\ No newline at end of file
diff --git a/cpp/autosar/src/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.ql b/cpp/autosar/src/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.ql
index ada60f305d..5c4d9d580f 100644
--- a/cpp/autosar/src/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.ql
+++ b/cpp/autosar/src/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.ql
@@ -28,7 +28,7 @@ where
    *    not use any of 'signal.h's facilities, for example.
    */
 
-  filename = i.getIncludedFile().getBaseName() and
+  filename = i.getIncludeText().substring(1, i.getIncludeText().length() - 1) and
   filename in [
       "assert.h", "ctype.h", "errno.h", "fenv.h", "float.h", "inttypes.h", "limits.h", "locale.h",
       "math.h", "setjmp.h", "signal.h", "stdarg.h", "stddef.h", "stdint.h", "stdio.h", "stdlib.h",
diff --git a/cpp/autosar/test/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.expected b/cpp/autosar/test/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.expected
index 3952555595..ff53ffd841 100644
--- a/cpp/autosar/test/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.expected
+++ b/cpp/autosar/test/rules/A18-0-1/CLibraryFacilitiesNotAccessedThroughCPPLibraryHeaders.expected
@@ -19,3 +19,4 @@
 | test.cpp:19:1:19:18 | #include <uchar.h> | C library "uchar.h" is included instead of the corresponding C++ library <cuchar>. |
 | test.cpp:20:1:20:18 | #include <wchar.h> | C library "wchar.h" is included instead of the corresponding C++ library <cwchar>. |
 | test.cpp:21:1:21:19 | #include <wctype.h> | C library "wctype.h" is included instead of the corresponding C++ library <cwctype>. |
+| test.cpp:45:1:45:17 | #include "time.h" | C library "time.h" is included instead of the corresponding C++ library <ctime>. |
diff --git a/cpp/autosar/test/rules/A18-0-1/lib/example.h b/cpp/autosar/test/rules/A18-0-1/lib/example.h
new file mode 100644
index 0000000000..001980b02f
--- /dev/null
+++ b/cpp/autosar/test/rules/A18-0-1/lib/example.h
@@ -0,0 +1,4 @@
+#ifndef LIB_EXAMPLE_H_
+#define LIB_EXAMPLE_H_
+
+#endif
\ No newline at end of file
diff --git a/cpp/autosar/test/rules/A18-0-1/test.cpp b/cpp/autosar/test/rules/A18-0-1/test.cpp
index b095017685..579842ddab 100644
--- a/cpp/autosar/test/rules/A18-0-1/test.cpp
+++ b/cpp/autosar/test/rules/A18-0-1/test.cpp
@@ -39,4 +39,7 @@
 #include <ctime>     // COMPLIANT
 #include <cuchar>    // COMPLIANT
 #include <cwchar>    // COMPLIANT
-#include <cwctype>   // COMPLIANT
\ No newline at end of file
+#include <cwctype>   // COMPLIANT
+
+#include "lib/example.h" // COMPLIANT
+#include "time.h"        // NON_COMPLIANT
\ No newline at end of file
diff --git a/cpp/autosar/test/rules/A18-0-1/time.h b/cpp/autosar/test/rules/A18-0-1/time.h
new file mode 100644
index 0000000000..ba58b95bbc
--- /dev/null
+++ b/cpp/autosar/test/rules/A18-0-1/time.h
@@ -0,0 +1,4 @@
+#ifndef LIB_TIME_EXAMPLE_H_
+#define LIB_TIME_EXAMPLE_H_
+// may be a user lib or a std lib checked into a project
+#endif
\ No newline at end of file