diff --git a/BUILD.gn b/BUILD.gn
index 2be010e..3ff387a 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -316,7 +316,11 @@
   if (is_win) {
     cflags = [ "/arch:AVX2" ]
   } else {
-    cflags = [ "-march=haswell" ]
+    cflags = [
+      "-mavx2",
+      "-mf16c",
+      "-mfma",
+    ]
   }
 
   # Oddly, clang-cl doesn't recognize this as a valid flag.