diff --git a/src/formal/vector_1D_s.F90 b/src/formal/vector_1D_s.F90
index 6410b31..cdc71a1 100644
--- a/src/formal/vector_1D_s.F90
+++ b/src/formal/vector_1D_s.F90
@@ -150,7 +150,7 @@ pure function premultiply_diagonal(d,A) result(DA)
 
       allocate(DA, mold=A)
 
-#ifdef HAVE_DO_CONCURRENT_TYPE_SPEC_SUPPORT && HAVE_LOCALITY_SPECIFIER_SUPPORT
+#if defined(HAVE_DO_CONCURRENT_TYPE_SPEC_SUPPORT) && defined(HAVE_LOCALITY_SPECIFIER_SUPPORT)
       do concurrent(integer :: row = 1 : size(A,1)) default(none) shared(d, A, DA)
         DA(row,:) = d(row) * A(row,:)
       end do
@@ -173,7 +173,7 @@ pure function postmultiply_diagonal(A,d) result(AD)
 
       allocate(AD, mold=A)
 
-#ifdef HAVE_DO_CONCURRENT_TYPE_SPEC_SUPPORT && HAVE_LOCALITY_SPECIFIER_SUPPORT
+#if defined(HAVE_DO_CONCURRENT_TYPE_SPEC_SUPPORT) && defined(HAVE_LOCALITY_SPECIFIER_SUPPORT)
       do concurrent(integer :: column = 1 : size(A,2)) default(none) shared(d, A, AD)
         AD(:,column) = A(:,column) * d(column)
       end do