diff --git a/gvsbuild/projects/gstreamer.py b/gvsbuild/projects/gstreamer.py
index 4cd2ce658..1dd03d504 100644
--- a/gvsbuild/projects/gstreamer.py
+++ b/gvsbuild/projects/gstreamer.py
@@ -135,6 +135,7 @@ def __init__(self):
                 "ninja",
                 "gst-plugins-base",
                 "libvpx",
+                "mpg123",
             ],
         )
 
diff --git a/gvsbuild/projects/mpg123.py b/gvsbuild/projects/mpg123.py
new file mode 100644
index 000000000..c173b8334
--- /dev/null
+++ b/gvsbuild/projects/mpg123.py
@@ -0,0 +1,46 @@
+#  Copyright (C) 2016 The Gvsbuild Authors
+#
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+from gvsbuild.utils.base_builders import CmakeProject
+from gvsbuild.utils.base_expanders import Tarball
+from gvsbuild.utils.base_project import Project, project_add
+
+
+@project_add
+class Mpg123(Tarball, CmakeProject):
+    def __init__(self):
+        Project.__init__(
+            self,
+            "mpg123",
+            version="1.33.7",
+            repository="https://www.mpg123.de",
+            archive_url="https://www.mpg123.de/download/mpg123-{version}.tar.bz2",
+            hash="31d0e35a4ca567ec9b5ebda6c3062bb4435d6d3eacd6ef0d95cadd7854dc03ee",
+            dependencies=["cmake", "ninja"],
+        )
+
+    def build(self):
+        # The CMake build lives in ports/cmake. Only the library is needed by
+        # gst-plugins-good's mpg123 element: no programs, no libout123/libsyn123.
+        CmakeProject.build(
+            self,
+            cmake_params=[
+                "-DBUILD_SHARED_LIBS=ON",
+                "-DBUILD_LIBOUT123=OFF",
+            ],
+            use_ninja=True,
+            source_part="ports/cmake",
+        )
+        self.install(r".\COPYING share\doc\mpg123")