diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
index a794fc8ba..f4fda5bb2 100644
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -2077,6 +2077,7 @@
                             "-DLLVM_ENABLE_ASSERTIONS=ON",
                             "-DCMAKE_C_COMPILER_LAUNCHER=ccache",
                             "-DCMAKE_CXX_COMPILER_LAUNCHER=ccache",
+                            "-DFLANG_RUNTIME_F128_MATH_LIB=libquadmath",
                             "-DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON",
                             "-DCMAKE_CXX_STANDARD=17",
                             "-DBUILD_SHARED_LIBS=ON",