diff --git a/lib/spack/spack/compilers/fj.py b/lib/spack/spack/compilers/fj.py
index c2cc66e1103..fb1b70df701 100644
--- a/lib/spack/spack/compilers/fj.py
+++ b/lib/spack/spack/compilers/fj.py
@@ -34,9 +34,13 @@ class Fj(spack.compiler.Compiler):
     def verbose_flag(self):
         return "-v"
 
+    @property
+    def debug_flags(self):
+        return "-g"
+
     @property
     def opt_flags(self):
-        return ['-O', '-O0', '-O1', '-O2', '-O3', '-O4']
+        return ['-O0', '-O1', '-O2', '-O3', '-Ofast']
 
     @property
     def openmp_flag(self):
@@ -54,6 +58,10 @@ def cxx11_flag(self):
     def cxx14_flag(self):
         return "-std=c++14"
 
+    @property
+    def cxx17_flag(self):
+        return "-std=c++17"
+
     @property
     def c99_flag(self):
         return "-std=c99"
diff --git a/lib/spack/spack/test/compilers/basics.py b/lib/spack/spack/test/compilers/basics.py
index 78d8484b3be..c33d878e0fe 100644
--- a/lib/spack/spack/test/compilers/basics.py
+++ b/lib/spack/spack/test/compilers/basics.py
@@ -471,14 +471,16 @@ def test_fj_flags():
     supported_flag_test("cxx98_flag", "-std=c++98", "fj@4.0.0")
     supported_flag_test("cxx11_flag", "-std=c++11", "fj@4.0.0")
     supported_flag_test("cxx14_flag", "-std=c++14", "fj@4.0.0")
+    supported_flag_test("cxx17_flag", "-std=c++17", "fj@4.0.0")
     supported_flag_test("c99_flag", "-std=c99", "fj@4.0.0")
     supported_flag_test("c11_flag", "-std=c11", "fj@4.0.0")
     supported_flag_test("cc_pic_flag",  "-KPIC", "fj@4.0.0")
     supported_flag_test("cxx_pic_flag", "-KPIC", "fj@4.0.0")
     supported_flag_test("f77_pic_flag", "-KPIC", "fj@4.0.0")
     supported_flag_test("fc_pic_flag",  "-KPIC", "fj@4.0.0")
-    supported_flag_test("opt_flags", ['-O', '-O0', '-O1', '-O2', '-O3', '-O4'],
+    supported_flag_test("opt_flags", ['-O0', '-O1', '-O2', '-O3', '-Ofast'],
                         'fj@4.0.0')
+    supported_flag_test("debug_flags", "-g", "fj@4.0.0")
 
 
 def test_gcc_flags():