diff --git a/pkgs/development/tools/build-managers/jam/default.nix b/pkgs/development/tools/build-managers/jam/default.nix
index 2a40c5970984..bf06954df4de 100644
--- a/pkgs/development/tools/build-managers/jam/default.nix
+++ b/pkgs/development/tools/build-managers/jam/default.nix
@@ -7,6 +7,9 @@ let
     depsBuildBuild = [ buildPackages.stdenv.cc ];
     nativeBuildInputs = [ bison ];
 
+    # Jam uses c89 conventions
+    env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-std=c89";
+
     # Jambase expects ar to have flags.
     preConfigure = ''
       export AR="$AR rc"