diff --git a/src/commands/CmdDiagnostics.cpp b/src/commands/CmdDiagnostics.cpp
index 591f080fd..e8e219cc7 100644
--- a/src/commands/CmdDiagnostics.cpp
+++ b/src/commands/CmdDiagnostics.cpp
@@ -134,6 +134,22 @@ int CmdDiagnostics::execute (std::string& output)
       << " +l"      << 8 * sizeof (long)
       << " +vp"     << 8 * sizeof (void*)
       << " +time_t" << 8 * sizeof (time_t)
+      << "\n";
+
+  // Compiler compliance level.
+  std::string compliance = "non-compliant";
+#ifdef __cplusplus
+  int level = __cplusplus;
+  if (level == 199711)
+    compliance = "C++98/03";
+  else if (level == 201103)
+    compliance = "C++11";
+  else
+    compliance = format (level);
+#endif
+  out << " " << STRING_CMD_DIAG_COMPLIANCE
+      << ": "
+      << compliance
       << "\n\n";
 
   out << bold.colorize (STRING_CMD_DIAG_FEATURES)
diff --git a/src/l10n/eng-USA.h b/src/l10n/eng-USA.h
index 0e5bf7527..8091d2f02 100644
--- a/src/l10n/eng-USA.h
+++ b/src/l10n/eng-USA.h
@@ -494,6 +494,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Compiler"
 #define STRING_CMD_DIAG_VERSION      "Version"
 #define STRING_CMD_DIAG_CAPS         "Caps"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Build Features"
 #define STRING_CMD_DIAG_BUILT        "Built"
 #define STRING_CMD_DIAG_COMMIT       "Commit"
diff --git a/src/l10n/epo-RUS.h b/src/l10n/epo-RUS.h
index 6b71fccca..c7657d6e0 100644
--- a/src/l10n/epo-RUS.h
+++ b/src/l10n/epo-RUS.h
@@ -494,6 +494,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Kompililo"
 #define STRING_CMD_DIAG_VERSION      "Versio"
 #define STRING_CMD_DIAG_CAPS         "Eblecoj"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Trajtoj de la Kompilo"
 #define STRING_CMD_DIAG_BUILT        "Kompilita"
 #define STRING_CMD_DIAG_COMMIT       "Ŝanĝaro"
diff --git a/src/l10n/esp-ESP.h b/src/l10n/esp-ESP.h
index 20226c7ae..45ff07ad0 100644
--- a/src/l10n/esp-ESP.h
+++ b/src/l10n/esp-ESP.h
@@ -503,6 +503,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Compilador"
 #define STRING_CMD_DIAG_VERSION      "Versión"
 #define STRING_CMD_DIAG_CAPS         "Capacidades"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Características Constructivas"
 #define STRING_CMD_DIAG_BUILT        "Construido"
 #define STRING_CMD_DIAG_COMMIT       "Commit"  // |esp-ESP|==|eng-USA|
diff --git a/src/l10n/fra-FRA.h b/src/l10n/fra-FRA.h
index 76d84edc9..b96561dab 100644
--- a/src/l10n/fra-FRA.h
+++ b/src/l10n/fra-FRA.h
@@ -493,6 +493,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Compiler"
 #define STRING_CMD_DIAG_VERSION      "Version"
 #define STRING_CMD_DIAG_CAPS         "Caps"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Build Features"
 #define STRING_CMD_DIAG_BUILT        "Built"
 #define STRING_CMD_DIAG_COMMIT       "Commit"
diff --git a/src/l10n/ita-ITA.h b/src/l10n/ita-ITA.h
index baa687dc9..4d0e2f2d3 100644
--- a/src/l10n/ita-ITA.h
+++ b/src/l10n/ita-ITA.h
@@ -494,6 +494,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Compilatore"
 #define STRING_CMD_DIAG_VERSION      "Versione"
 #define STRING_CMD_DIAG_CAPS         "Caps"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Caratteristiche della Build"
 #define STRING_CMD_DIAG_BUILT        "Generato"
 #define STRING_CMD_DIAG_COMMIT       "Commit"
diff --git a/src/l10n/pol-POL.h b/src/l10n/pol-POL.h
index f1a58ea51..cbf532430 100644
--- a/src/l10n/pol-POL.h
+++ b/src/l10n/pol-POL.h
@@ -494,6 +494,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Kompilator"
 #define STRING_CMD_DIAG_VERSION      "Wersja"
 #define STRING_CMD_DIAG_CAPS         "Flagi"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Opcje budowania"
 #define STRING_CMD_DIAG_BUILT        "Zbudowano"
 #define STRING_CMD_DIAG_COMMIT       "Zatwierdzenie"
diff --git a/src/l10n/por-PRT.h b/src/l10n/por-PRT.h
index 53601a5a0..1b5b449ce 100644
--- a/src/l10n/por-PRT.h
+++ b/src/l10n/por-PRT.h
@@ -494,6 +494,7 @@
 #define STRING_CMD_DIAG_COMPILER     "Compilador"
 #define STRING_CMD_DIAG_VERSION      "Versão"
 #define STRING_CMD_DIAG_CAPS         "Capacidades"
+#define STRING_CMD_DIAG_COMPLIANCE   "Compliance"
 #define STRING_CMD_DIAG_FEATURES     "Características da versão"
 #define STRING_CMD_DIAG_BUILT        "Criado"
 #define STRING_CMD_DIAG_COMMIT       "Commit"  // |por-PRT|==|eng-USA|