diff --git a/var/spack/repos/builtin/packages/petsc/package.py b/var/spack/repos/builtin/packages/petsc/package.py
index 99800b501..b40173fe6 100644
--- a/var/spack/repos/builtin/packages/petsc/package.py
+++ b/var/spack/repos/builtin/packages/petsc/package.py
@@ -195,10 +195,7 @@ class Petsc(Package):
                    '--download-hwloc=0',
                    'CFLAGS=%s' % ' '.join(spec.compiler_flags['cflags']),
                    'FFLAGS=%s' % ' '.join(spec.compiler_flags['fflags']),
-                   'CXXFLAGS=%s' % ' '.join(spec.compiler_flags['cxxflags']),
-                   'COPTFLAGS=',
-                   'FOPTFLAGS=',
-                   'CXXOPTFLAGS=']
+                   'CXXFLAGS=%s' % ' '.join(spec.compiler_flags['cxxflags'])]
         options.extend(self.mpi_dependent_options())
         options.extend([
             '--with-precision=%s' % (
@@ -209,6 +206,13 @@ class Petsc(Package):
             '--with-debugging=%s' % ('1' if '+debug' in spec else '0'),
             '--with-64-bit-indices=%s' % ('1' if '+int64' in spec else '0')
         ])
+        if '+debug' in spec:
+            options.append('--with-debugging=%s')
+        else:
+            options.extend(['COPTFLAGS=',
+                            'FOPTFLAGS=',
+                            'CXXOPTFLAGS='])
+
         # Make sure we use exactly the same Blas/Lapack libraries
         # across the DAG. To that end list them explicitly
         lapack_blas = spec['lapack'].libs + spec['blas'].libs