diff --git a/README.md b/README.md
index 5ad1732..62cc7ae 100644
--- a/README.md
+++ b/README.md
@@ -797,7 +797,7 @@ builder                    (xml.builder)
 C                          (c, ec, pgc)
 C Shell                    (csh, tcsh)
 C#                         (cs)
-C++                        (C, c++, cc, cpp, cxx, pcc)
+C++                        (C, c++, cc, cpp, CPP, cxx, pcc)
 C/C++ Header               (h, H, hh, hpp, hxx)
 CCS                        (ccs)
 Clean                      (dcl, icl)
diff --git a/Unix/cloc b/Unix/cloc
index d17ecc3..bceda3f 100755
--- a/Unix/cloc
+++ b/Unix/cloc
@@ -5359,6 +5359,7 @@ sub set_constants {                          # {{{1
             'coffee'      => 'CoffeeScript'          ,
             'component'   => 'Visualforce Component' ,
             'cpp'         => 'C++'                   ,
+            'CPP'         => 'C++'                   ,
             'cr'          => 'Crystal'               ,
             'cs'          => 'C#'                    ,
             'csh'         => 'C Shell'               ,
diff --git a/Unix/results.yaml b/Unix/results.yaml
new file mode 100644
index 0000000..9c5f63d
--- /dev/null
+++ b/Unix/results.yaml
@@ -0,0 +1,21 @@
+---
+# github.com/AlDanial/cloc
+header : 
+  cloc_url           : github.com/AlDanial/cloc
+  cloc_version       : 1.73
+  elapsed_seconds    : 0.00850009918212891
+  n_files            : 1
+  n_lines            : 8
+  files_per_second   : 117.645686076517
+  lines_per_second   : 941.16548861214
+  report_file        : results.yaml
+XSLT :
+  nFiles: 1
+  blank: 0
+  comment: 2
+  code: 6
+SUM: 
+  blank: 0
+  comment: 2
+  code: 6
+  nFiles: 1
diff --git a/Unix/t/00_C.t b/Unix/t/00_C.t
index 85c46aa..55ddc2a 100755
--- a/Unix/t/00_C.t
+++ b/Unix/t/00_C.t
@@ -79,6 +79,11 @@ my @Tests = (   {
                     'args' => '../tests/inputs/C++-MFC.cc',
                 },
                 {
+                    'name' => 'C++ Uppercase extension',
+                    'ref'  => '../tests/outputs/C++-uppercase.CPP.yaml',
+                    'args' => '../tests/inputs/C++-uppercase.CPP',
+                },
+                {
                     'name' => 'C simple',
                     'ref'  => '../tests/outputs/C-Ansi.c.yaml',
                     'args' => '../tests/inputs/C-Ansi.c',
diff --git a/cloc b/cloc
index 070a551..9db3699 100755
--- a/cloc
+++ b/cloc
@@ -5392,6 +5392,7 @@ sub set_constants {                          # {{{1
             'coffee'      => 'CoffeeScript'          ,
             'component'   => 'Visualforce Component' ,
             'cpp'         => 'C++'                   ,
+            'CPP'         => 'C++'                   ,
             'cr'          => 'Crystal'               ,
             'cs'          => 'C#/Smalltalk'          ,
             'csh'         => 'C Shell'               ,
diff --git a/tests/inputs/C++-uppercase.CPP b/tests/inputs/C++-uppercase.CPP
new file mode 100644
index 0000000..bb6f548
--- /dev/null
+++ b/tests/inputs/C++-uppercase.CPP
@@ -0,0 +1,4 @@
+// Comment
+
+int main() {}
+
diff --git a/tests/outputs/C++-uppercase.CPP.yaml b/tests/outputs/C++-uppercase.CPP.yaml
new file mode 100644
index 0000000..3c76164
--- /dev/null
+++ b/tests/outputs/C++-uppercase.CPP.yaml
@@ -0,0 +1,21 @@
+---
+# github.com/AlDanial/cloc
+header :
+  cloc_url           : github.com/AlDanial/cloc
+  cloc_version       : 1.67
+  elapsed_seconds    : 0.00526905059814453
+  n_files            : 1
+  n_lines            : 1
+  files_per_second   : 189.787511312217
+  lines_per_second   : 5693.62533936652
+  report_file        : C++-uppercase.CPP.yaml
+C++ :
+  nFiles: 1
+  blank: 2
+  comment: 1
+  code: 1
+SUM:
+  blank: 2
+  comment: 1
+  code: 1
+  nFiles: 1