diff --git a/content/code/day-2/25_cxx-fortran/solution/src/math/CMakeLists.txt b/content/code/day-2/25_cxx-fortran/solution/src/math/CMakeLists.txt
index 2f9e1a4..bad632b 100644
--- a/content/code/day-2/25_cxx-fortran/solution/src/math/CMakeLists.txt
+++ b/content/code/day-2/25_cxx-fortran/solution/src/math/CMakeLists.txt
@@ -7,7 +7,6 @@ FortranCInterface_VERIFY(CXX)
 
 FortranCInterface_HEADER(
   fc_mangle.h
-  MACRO_NAMESPACE "FC_"
   SYMBOLS DSCAL DGESV
   )
 
diff --git a/content/code/day-2/25_cxx-fortran/solution/src/math/CxxBLAS.cpp b/content/code/day-2/25_cxx-fortran/solution/src/math/CxxBLAS.cpp
index 3d22c1e..ed23dcc 100644
--- a/content/code/day-2/25_cxx-fortran/solution/src/math/CxxBLAS.cpp
+++ b/content/code/day-2/25_cxx-fortran/solution/src/math/CxxBLAS.cpp
@@ -11,6 +11,6 @@ void C_DSCAL(size_t length, double alpha, double *vec, int inc) {
   for (int block = 0; block <= big_blocks; block++) {
     double *vec_s = &vec[block * inc * (size_t)INT_MAX];
     signed int length_s = (block == big_blocks) ? small_size : INT_MAX;
-    ::DSCAL(&length_s, &alpha, vec_s, &inc);
+    DSCAL(&length_s, &alpha, vec_s, &inc);
   }
 }
diff --git a/content/code/day-2/25_cxx-fortran/solution/src/math/CxxLAPACK.cpp b/content/code/day-2/25_cxx-fortran/solution/src/math/CxxLAPACK.cpp
index 67e8021..39ce4c6 100644
--- a/content/code/day-2/25_cxx-fortran/solution/src/math/CxxLAPACK.cpp
+++ b/content/code/day-2/25_cxx-fortran/solution/src/math/CxxLAPACK.cpp
@@ -5,6 +5,6 @@
 // see http://www.netlib.no/netlib/lapack/double/dgesv.f
 int C_DGESV(int n, int nrhs, double *a, int lda, int *ipiv, double *b, int ldb) {
   int info;
-  ::DGESV(&n, &nrhs, a, &lda, ipiv, b, &ldb, &info);
+  DGESV(&n, &nrhs, a, &lda, ipiv, b, &ldb, &info);
   return info;
 }
diff --git a/content/code/day-2/25_cxx-fortran/src/math/CMakeLists.txt b/content/code/day-2/25_cxx-fortran/src/math/CMakeLists.txt
index 7b0a6f6..3321018 100644
--- a/content/code/day-2/25_cxx-fortran/src/math/CMakeLists.txt
+++ b/content/code/day-2/25_cxx-fortran/src/math/CMakeLists.txt
@@ -9,7 +9,6 @@ include(...)
 # FIXME generate Fortran name mangling header
 FortranCInterface_HEADER(
   ...
-  MACRO_NAMESPACE ...
   SYMBOLS ...
   )