diff --git a/var/spack/repos/builtin/packages/superlu-dist/package.py b/var/spack/repos/builtin/packages/superlu-dist/package.py
index 7af57369933..241dc4b552c 100644
--- a/var/spack/repos/builtin/packages/superlu-dist/package.py
+++ b/var/spack/repos/builtin/packages/superlu-dist/package.py
@@ -134,8 +134,6 @@ def flag_handler(self, name, flags):
         flags = list(flags)
         if name == "cxxflags":
             flags.append(self.compiler.cxx11_flag)
-        if name == "cflags" and "%pgi" not in self.spec:
-            flags.append("-std=c99")
         if (
             name == "cflags"
             and (self.spec.satisfies("%xl") or self.spec.satisfies("%xl_r"))