diff --git a/setup.py b/setup.py
index 61f16cd82eb33abc7f64c0e0375fca7c68a23064..218996ebb7dfded7323ff281d7d7bec0c82d2844 100644
--- a/setup.py
+++ b/setup.py
@@ -41,9 +41,14 @@ DASH_SEPARATOR = 75 * "-"
 
 def main():
     import os
-    build_mode = os.environ.get("PYFMMLIB_BUILD_MODE", "openmp-opt")
+    build_mode = os.environ.get("PYFMMLIB_BUILD_MODE", "openmp-ofast")
 
-    if build_mode == "openmp-opt":
+    if build_mode == "openmp-ofast":
+        os.environ["FOPT"] = "-Ofast -fopenmp"
+        os.environ["OPT"] = "-Ofast -fopenmp"
+        os.environ["EXTRA_LINK_ARGS"] = "-fopenmp"
+
+    elif build_mode == "openmp-opt":
         os.environ["FOPT"] = "-O3 -fopenmp"
         os.environ["OPT"] = "-O3 -fopenmp"
         os.environ["EXTRA_LINK_ARGS"] = "-fopenmp"