diff --git a/cli/mainfeatures.cpp b/cli/mainfeatures.cpp
index d3f256a..5303ed2 100644
--- a/cli/mainfeatures.cpp
+++ b/cli/mainfeatures.cpp
@@ -18,6 +18,7 @@
 #include <tagparser/abstracttrack.h>
 #include <tagparser/backuphelper.h>
 #include <tagparser/diagnostics.h>
+#include <tagparser/language.h>
 #include <tagparser/mediafileinfo.h>
 #include <tagparser/progressfeedback.h>
 #include <tagparser/tag.h>
@@ -198,8 +199,8 @@ void displayFileInfo(const ArgumentOccurrence &, const Argument &filesArg, const
                     printProperty("ID", track->id(), nullptr, true);
                     printProperty("Name", track->name());
                     printProperty("Type", track->mediaTypeName());
-                    if (track->language() != "und") {
-                        printProperty("Language", track->language());
+                    if (isLanguageDefined(track->language())) {
+                        printProperty("Language", languageNameFromIsoWithFallback(track->language()));
                     }
                     const char *fmtName = track->formatName(), *fmtAbbr = track->formatAbbreviation();
                     printProperty("Format", fmtName);
diff --git a/gui/fileinfomodel.cpp b/gui/fileinfomodel.cpp
index f00231a..d0d8ee0 100644
--- a/gui/fileinfomodel.cpp
+++ b/gui/fileinfomodel.cpp
@@ -7,6 +7,7 @@
 #include <tagparser/abstractcontainer.h>
 #include <tagparser/abstracttrack.h>
 #include <tagparser/diagnostics.h>
+#include <tagparser/language.h>
 #include <tagparser/matroska/matroskacontainer.h>
 #include <tagparser/matroska/matroskaeditionentry.h>
 #include <tagparser/mediafileinfo.h>
@@ -415,7 +416,7 @@ void FileInfoModel::updateCache()
                     }
                     trackHelper.appendRow(tr("Creation time"), track->creationTime());
                     trackHelper.appendRow(tr("Modification time"), track->modificationTime());
-                    trackHelper.appendRow(tr("Language"), track->language());
+                    trackHelper.appendRow(tr("Language"), languageNameFromIsoWithFallback(track->language()));
                     trackHelper.appendRow(tr("Compressor name"), track->compressorName());
                     if (track->samplingFrequency()) {
                         trackHelper.appendRow(tr("Sampling frequency"),
diff --git a/misc/htmlinfo.cpp b/misc/htmlinfo.cpp
index d7394e6..2a41fd6 100644
--- a/misc/htmlinfo.cpp
+++ b/misc/htmlinfo.cpp
@@ -6,6 +6,7 @@
 #include <tagparser/abstractattachment.h>
 #include <tagparser/abstractcontainer.h>
 #include <tagparser/abstracttrack.h>
+#include <tagparser/language.h>
 #include <tagparser/matroska/matroskacontainer.h>
 #include <tagparser/matroska/matroskaeditionentry.h>
 #include <tagparser/mediafileinfo.h>
@@ -587,7 +588,7 @@ public:
                 qstr(track->modificationTime().toString(DateTimeOutputFormat::DateAndTime, true)));
         }
         if (!track->language().empty()) {
-            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Language"), qstr(track->language()));
+            rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Language"), qstr(languageNameFromIsoWithFallback(track->language())));
         }
         if (!track->compressorName().empty()) {
             rowMaker.mkRow(QCoreApplication::translate("HtmlInfo", "Compressor name"), qstr(track->compressorName()));
diff --git a/tests/cli.cpp b/tests/cli.cpp
index ee0d15f..1523cbf 100644
--- a/tests/cli.cpp
+++ b/tests/cli.cpp
@@ -828,7 +828,7 @@ void CliTests::testSettingTrackMetaData()
             "    ID                            3134325680\n"
             "    Name                          audio track\n"
             "    Type                          Audio\n"
-            "    Language                      ger\n"
+            "    Language                      German\n"
             "    Format                        Advanced Audio Coding Low Complexity Profile\n"
             "    Abbreviation                  MPEG-4 AAC-LC\n"
             "    Raw format ID                 A_AAC\n"
@@ -858,7 +858,7 @@ void CliTests::testSettingTrackMetaData()
             "    ID                            1\n"
             "    Name                          sbr and ps\n"
             "    Type                          Audio\n"
-            "    Language                      eng\n"
+            "    Language                      English\n"
             "    Format                        Advanced Audio Coding Low Complexity Profile\n"
             "    Abbreviation                  MPEG-4 AAC-LC\n"
             "    Extensions                    Spectral Band Replication and Parametric Stereo / HE-AAC v2\n"