diff --git a/pkgs/by-name/ud/udunits/package.nix b/pkgs/by-name/ud/udunits/package.nix
index 1356976271fc..d87e75af72dc 100644
--- a/pkgs/by-name/ud/udunits/package.nix
+++ b/pkgs/by-name/ud/udunits/package.nix
@@ -32,6 +32,10 @@ stdenv.mkDerivation {
     expat
   ];
 
+  configureFlags = [
+    "CFLAGS=-std=gnu17"
+  ];
+
   meta = {
     homepage = "https://www.unidata.ucar.edu/software/udunits/";
     description = "C-based package for the programatic handling of units of physical quantities";