diff --git a/pkgs/development/tools/misc/gnum4/default.nix b/pkgs/development/tools/misc/gnum4/default.nix
index ab2ab0de9cf9..b01f85bb4a7a 100644
--- a/pkgs/development/tools/misc/gnum4/default.nix
+++ b/pkgs/development/tools/misc/gnum4/default.nix
@@ -13,7 +13,14 @@ stdenv.mkDerivation {
   configureFlags = [ "--with-syscmd-shell=${stdenv.shell}" ];
 
   # Upstream is aware of it; it may be in the next release.
-  patches = [ ./s_isdir.patch ]
+  patches =
+    [
+      ./s_isdir.patch
+      (fetchurl {
+        url = "https://sources.debian.org/data/main/m/m4/1.4.18-2/debian/patches/01-fix-ftbfs-with-glibc-2.28.patch";
+        sha256 = "12lmdnbml9lfvy0khpjc42riicddaz7li8wmbnsam7zsw6al11qk";
+      })
+    ]
     ++ stdenv.lib.optional stdenv.isDarwin ./darwin-secure-format.patch;
 
   meta = {