diff --git a/b/Boost/Boost-1.61.0-foss-2017a-serial.eb b/b/Boost/Boost-1.61.0-foss-2017a-serial.eb
index 9863e153..964fd23c 100644
--- a/b/Boost/Boost-1.61.0-foss-2017a-serial.eb
+++ b/b/Boost/Boost-1.61.0-foss-2017a-serial.eb
@@ -12,8 +12,8 @@ source_urls = [SOURCEFORGE_SOURCE]
 sources = ['%%(namelower)s_%s.tar.gz' % '_'.join(version.split('.'))]
 
 dependencies = [
-    ('bzip2', '1.0.6'),
-    ('zlib', '1.2.11'),
+    ('bzip2', '1.0.6', '', True),
+    ('zlib', '1.2.11', '', True),
 ]
 
 configopts = '--with-libraries=serialization'
diff --git a/g/GCCcore/GCCcore-6.3.0.eb b/g/GCCcore/GCCcore-6.3.0.eb
index 86c90d40..9d4e7340 100644
--- a/g/GCCcore/GCCcore-6.3.0.eb
+++ b/g/GCCcore/GCCcore-6.3.0.eb
@@ -60,7 +60,6 @@ modextravars = {
     'DEBUGFLAGS': '-O0 -g'
 }
 
-
 withisl = True
 
 moduleclass = 'compiler'
diff --git a/g/GCCcore/GCCcore-7.1.0.eb b/g/GCCcore/GCCcore-7.1.0.eb
index 0ddfaa2e..dcdc37a2 100644
--- a/g/GCCcore/GCCcore-7.1.0.eb
+++ b/g/GCCcore/GCCcore-7.1.0.eb
@@ -51,4 +51,15 @@ languages = ['c', 'c++', 'fortran']
 
 withisl = True
 
+modextravars = {
+    'CC': '%(installdir)s/bin/gcc',
+    'CXX': '%(installdir)s/bin/g++',
+    'F90': '%(installdir)s/bin/gfortran',
+    'F77': '%(installdir)s/bin/gfortran',
+    'FC': '%(installdir)s/bin/gfortran',
+    'F9X': '%(installdir)s/bin/gfortran',
+    'OPTFLAGS': '-O3 -march=native',
+    'DEBUGFLAGS': '-O0 -g'
+}
+
 moduleclass = 'compiler'
diff --git a/i/impi/impi-2017.0.098-iccifort-2017.0.098-GCC-5.4.0-2.26.eb b/i/impi/impi-2017.0.098-iccifort-2017.0.098-GCC-5.4.0-2.26.eb
index 769383cf..dc267bfd 100644
--- a/i/impi/impi-2017.0.098-iccifort-2017.0.098-GCC-5.4.0-2.26.eb
+++ b/i/impi/impi-2017.0.098-iccifort-2017.0.098-GCC-5.4.0-2.26.eb
@@ -32,4 +32,14 @@ postinstallcmds = [
     'ln -s %(installdir)s/lib64/libmpi.so %(installdir)s/lib64/libopa.so'
 ]
 
+modextravars = {
+    'I_MPI_CC': 'icc',
+    'I_MPI_CXX': 'icpc',
+    'I_MPI_F77': 'ifort',
+    'I_MPI_F90': 'ifort',
+    'I_MPI_FC': 'ifort',
+    'I_MPI_EXTRA_FILESYSTEM': 'enable',
+    'I_MPI_EXTRA_FILESYSTEM_LIST': 'lustre',
+}
+
 moduleclass = 'mpi'
diff --git a/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-5.4.0-2.26.eb b/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-5.4.0-2.26.eb
index abb69311..0f633e34 100644
--- a/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-5.4.0-2.26.eb
+++ b/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-5.4.0-2.26.eb
@@ -32,4 +32,14 @@ postinstallcmds = [
     'ln -s %(installdir)s/lib64/libmpi.so %(installdir)s/lib64/libopa.so'
 ]
 
+modextravars = {
+    'I_MPI_CC': 'icc',
+    'I_MPI_CXX': 'icpc',
+    'I_MPI_F77': 'ifort',
+    'I_MPI_F90': 'ifort',
+    'I_MPI_FC': 'ifort',
+    'I_MPI_EXTRA_FILESYSTEM': 'enable',
+    'I_MPI_EXTRA_FILESYSTEM_LIST': 'lustre',
+}
+
 moduleclass = 'mpi'
diff --git a/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-6.3.0-2.27.eb b/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-6.3.0-2.27.eb
index 1f81018b..1cee9da1 100644
--- a/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-6.3.0-2.27.eb
+++ b/i/impi/impi-2017.1.132-iccifort-2017.1.132-GCC-6.3.0-2.27.eb
@@ -32,4 +32,14 @@ postinstallcmds = [
     'ln -s %(installdir)s/lib64/libmpi.so %(installdir)s/lib64/libopa.so'
 ]
 
+modextravars = {
+    'I_MPI_CC': 'icc',
+    'I_MPI_CXX': 'icpc',
+    'I_MPI_F77': 'ifort',
+    'I_MPI_F90': 'ifort',
+    'I_MPI_FC': 'ifort',
+    'I_MPI_EXTRA_FILESYSTEM': 'enable',
+    'I_MPI_EXTRA_FILESYSTEM_LIST': 'lustre',
+}
+
 moduleclass = 'mpi'
diff --git a/i/impi/impi-2017.3.196-iccifort-2017.4.196-GCC-7.1.0-2.28.eb b/i/impi/impi-2017.3.196-iccifort-2017.4.196-GCC-7.1.0-2.28.eb
index a2662c14..420ef26e 100644
--- a/i/impi/impi-2017.3.196-iccifort-2017.4.196-GCC-7.1.0-2.28.eb
+++ b/i/impi/impi-2017.3.196-iccifort-2017.4.196-GCC-7.1.0-2.28.eb
@@ -30,4 +30,14 @@ postinstallcmds = [
     'ln -s %(installdir)s/lib64/libmpi.so %(installdir)s/lib64/libopa.so'
 ]
 
+modextravars = {
+    'I_MPI_CC': 'icc',
+    'I_MPI_CXX': 'icpc',
+    'I_MPI_F77': 'ifort',
+    'I_MPI_F90': 'ifort',
+    'I_MPI_FC': 'ifort',
+    'I_MPI_EXTRA_FILESYSTEM': 'enable',
+    'I_MPI_EXTRA_FILESYSTEM_LIST': 'lustre',
+}
+
 moduleclass = 'mpi'