diff --git a/easybuild/tools/toolchain/constants.py b/easybuild/tools/toolchain/constants.py
index 643e8b4d21..71a683e3c3 100644
--- a/easybuild/tools/toolchain/constants.py
+++ b/easybuild/tools/toolchain/constants.py
@@ -31,9 +31,9 @@
 * Kenneth Hoste (Ghent University)
 """
 
-from easybuild.tools.variables import AbsPathList
-from easybuild.tools.toolchain.variables import CommandFlagList, CommaSharedLibs, CommaStaticLibs
-from easybuild.tools.toolchain.variables import FlagList, IncludePaths, LibraryList, LinkLibraryPaths
+from easybuild.tools.variables import AbsPathList, StrList
+from easybuild.tools.toolchain.variables import CommaSharedLibs, CommaStaticLibs
+from easybuild.tools.toolchain.variables import IncludePaths, LibraryList, LinkLibraryPaths
 
 
 COMPILER_VARIABLES = [
@@ -53,10 +53,10 @@
 ]
 
 COMPILER_MAP_CLASS = {
-    FlagList: [
+    StrList: [
         ('OPTFLAGS', 'Optimization flags'),
         ('PRECFLAGS', 'FP precision flags'),
-    ] + COMPILER_FLAGS,
+    ] + COMPILER_FLAGS + COMPILER_VARIABLES,
     LibraryList: [
         ('LIBS', 'Libraries'),  # TODO: where are these used? ld?
         ('FLIBS', 'Fortran libraries'),  # TODO: where are these used? gfortran only?
@@ -67,18 +67,15 @@
     IncludePaths: [
         ('CPPFLAGS', 'Precompiler flags'),
     ],
-    CommandFlagList: COMPILER_VARIABLES,
 }
 
 CO_COMPILER_MAP_CLASS = {
-    CommandFlagList: [
+    StrList: [
         ('CUDA_CC', 'CUDA C compiler command'),
         ('CUDA_CXX', 'CUDA C++ compiler command'),
         ('CUDA_F77', 'CUDA Fortran 77 compiler command'),
         ('CUDA_F90', 'CUDA Fortran 90 compiler command'),
         ('CUDA_FC', 'CUDA Fortran 77/90 compiler command'),
-    ],
-    FlagList: [
         ('CUDA_CFLAGS', 'CUDA C compiler flags'),
         ('CUDA_CXXFLAGS', 'CUDA C++ compiler flags'),
         ('CUDA_FCFLAGS', 'CUDA Fortran 77/90 compiler flags'),
@@ -103,7 +100,7 @@
         ('MPI_LIB_DIR', 'MPI library directory'),
         ('MPI_INC_DIR', 'MPI include directory'),
     ],
-    CommandFlagList: MPI_COMPILER_VARIABLES + SEQ_COMPILER_VARIABLES,
+    StrList: MPI_COMPILER_VARIABLES + SEQ_COMPILER_VARIABLES,
 }
 
 BLAS_MAP_CLASS = {
diff --git a/easybuild/tools/toolchain/toolchainvariables.py b/easybuild/tools/toolchain/toolchainvariables.py
index dbb5686040..299db0f0a3 100644
--- a/easybuild/tools/toolchain/toolchainvariables.py
+++ b/easybuild/tools/toolchain/toolchainvariables.py
@@ -33,7 +33,8 @@
 
 from easybuild.tools.variables import Variables, join_map_class
 from easybuild.tools.toolchain.constants import ALL_MAP_CLASSES
-from easybuild.tools.toolchain.variables import LinkerFlagList, FlagList
+from easybuild.tools.toolchain.variables import LinkerFlagList
+from easybuild.tools.variables import StrList
 
 
 class ToolchainVariables(Variables):
@@ -42,7 +43,7 @@ class ToolchainVariables(Variables):
     in context of compilers (i.e. the generated string are e.g. compiler options or link flags)
     """
     MAP_CLASS = join_map_class(ALL_MAP_CLASSES)  # join_map_class strips explanation
-    DEFAULT_CLASS = FlagList
+    DEFAULT_CLASS = StrList
     LINKER_TOGGLE_START_STOP_GROUP = None
     LINKER_TOGGLE_STATIC_DYNAMIC = None