diff --git a/Misc/NEWS.d/next/Build/2020-07-15-17-56-32.bpo-41302.S3o-x9.rst b/Misc/NEWS.d/next/Build/2020-07-15-17-56-32.bpo-41302.S3o-x9.rst
new file mode 100644
index 00000000000000..2f1301740e7484
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2020-07-15-17-56-32.bpo-41302.S3o-x9.rst
@@ -0,0 +1 @@
+Enable building Python 3.8 with libmpdec-2.5.0 to ease maintenance for Linux distributions. Patch by Felix Yan.
\ No newline at end of file
diff --git a/Modules/_decimal/_decimal.c b/Modules/_decimal/_decimal.c
index df7c6e254bcf29..eb1f1a01feeca8 100644
--- a/Modules/_decimal/_decimal.c
+++ b/Modules/_decimal/_decimal.c
@@ -58,6 +58,13 @@
 
 #define BOUNDS_CHECK(x, MIN, MAX) x = (x < MIN || MAX < x) ? MAX : x
 
+#ifndef UNUSED
+#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
+  #define UNUSED __attribute__((unused))
+#else
+  #define UNUSED
+#endif
+#endif
 
 /* _Py_DEC_MINALLOC >= MPD_MINALLOC */
 #define _Py_DEC_MINALLOC 4