diff --git a/SConstruct b/SConstruct
index f0b277312..fd374fa88 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1007,7 +1007,7 @@ def install(*args, **kwargs):
 
 env.SConsignFile()
 
-env.Append(CPPPATH=[],
+env.Prepend(CPPPATH=[],
            LIBPATH=[Dir('build/lib')])
 
 if addInstallActions:
diff --git a/ext/SConscript b/ext/SConscript
index 7989ef318..f5bd4f088 100644
--- a/ext/SConscript
+++ b/ext/SConscript
@@ -8,13 +8,13 @@ def prep_default(env):
 
 def prep_fortran(env):
     localenv = env.Clone()
-    localenv.Append(CPPPATH='#include/cantera/base') # for config.h
+    localenv.Prepend(CPPPATH='#include/cantera/base') # for config.h
     return localenv
 
 def prep_f2c(env):
     localenv = env.Clone()
 
-    localenv.Append(CPPPATH=Dir('#ext/f2c_libs'))
+    localenv.Prepend(CPPPATH=Dir('#ext/f2c_libs'))
     if not localenv['HAS_TIMES_H']:
         localenv.Append(CPPDEFINES=['USE_CLOCK'])
     if not localenv['HAS_UNISTD_H']:
@@ -37,7 +37,7 @@ def prep_f2c(env):
 
 def prep_sundials(env):
     localenv = env.Clone()
-    localenv.Append(CPPPATH=Dir('#ext/cvode/include'))
+    localenv.Prepend(CPPPATH=Dir('#ext/cvode/include'))
 
     # Suppress warnings from external code
     if '-Wall' in localenv['CCFLAGS']:
@@ -47,8 +47,8 @@ def prep_sundials(env):
 
 def prep_gtest(env):
     localenv = env.Clone()
-    localenv.Append(CPPPATH=[Dir('#ext/gtest'),
-                             Dir('#ext/gtest/include')],
+    localenv.Prepend(CPPPATH=[Dir('#ext/gtest'),
+                              Dir('#ext/gtest/include')],
                     CPPDEFINES={'GTEST_HAS_PTHREAD': 0})
     return localenv
 
@@ -132,8 +132,8 @@ for subdir, extensions, prepFunction in libs:
 
 
 localenv = env.Clone()
-localenv.Append(CPPPATH=[Dir('#ext/gtest'),
-                         Dir('#ext/gtest/include')],
+localenv.Prepend(CPPPATH=[Dir('#ext/gtest'),
+                          Dir('#ext/gtest/include')],
                 CPPDEFINES={'GTEST_HAS_PTHREAD': 0})
 build(localenv.Library(pjoin('../lib', 'gtest'),
                        source=['gtest/src/gtest-all.cc']))
diff --git a/src/SConscript b/src/SConscript
index 3072f5853..496fb0e94 100644
--- a/src/SConscript
+++ b/src/SConscript
@@ -39,8 +39,8 @@ libs = [('base', ['cpp'], baseSetup),
 
 for subdir, extensions, setup in libs:
     localenv = env.Clone()
-    localenv.Append(CPPPATH=Dir('#include'))
-    localenv.Append(CPPPATH=Dir('#src')) # todo: remove when not needed
+    localenv.Prepend(CPPPATH=Dir('#include'))
+    localenv.Prepend(CPPPATH=Dir('#src')) # todo: remove when not needed
     source = setup(localenv, subdir, extensions)
     objects = localenv.SharedObject(source)
     localenv.Depends(objects, localenv['config_h_target'])
diff --git a/src/apps/SConscript b/src/apps/SConscript
index 9b7f3034d..53b013e98 100644
--- a/src/apps/SConscript
+++ b/src/apps/SConscript
@@ -2,7 +2,7 @@ from buildutils import *
 
 Import('env', 'build', 'install')
 localenv = env.Clone()
-localenv.Append(CPPPATH=['#src', '#include', '#src/apps'])
+localenv.Prepend(CPPPATH=['#src', '#include', '#src/apps'])
 
 def buildProgram(name, src):
     prog = build(localenv.Program(target=pjoin('#build/bin', name),
diff --git a/src/fortran/SConscript b/src/fortran/SConscript
index c2c3b91d0..f84cd4757 100644
--- a/src/fortran/SConscript
+++ b/src/fortran/SConscript
@@ -3,7 +3,7 @@ from buildutils import *
 Import('env', 'build', 'install')
 
 localenv = env.Clone()
-localenv.Append(CPPPATH=['#include', '#src'])
+localenv.Prepend(CPPPATH=['#include', '#src'])
 
 f90_src = mglob(localenv, '.', 'f90', 'cpp')
 
diff --git a/src/matlab/SConscript b/src/matlab/SConscript
index 8513e993d..5e7a628ba 100644
--- a/src/matlab/SConscript
+++ b/src/matlab/SConscript
@@ -53,8 +53,8 @@ elif os.name == 'posix':
     linkflags.extend(['-Wl,--no-undefined',
                       '-Wl,--version-script,src/matlab/mexFunction.map'])
 
-localenv.Append(CPPPATH=['#include', '#src', matlab_include],
-                CPPDEFINES=['MATLAB_MEX_FILE'],
+localenv.Prepend(CPPPATH=['#include', '#src', matlab_include])
+localenv.Append(CPPDEFINES=['MATLAB_MEX_FILE'],
                 LIBPATH=[matlab_libs],
                 LINKFLAGS=linkflags)
 
diff --git a/src/python/SConscript b/src/python/SConscript
index f96f6d47f..9bb4bad3c 100644
--- a/src/python/SConscript
+++ b/src/python/SConscript
@@ -31,7 +31,7 @@ make_setup = localenv.SubstFile('#interfaces/python/setup.py',
 
 extraArgs = ''
 if localenv['python_package'] == 'full':
-    localenv.Append(CPPPATH=['#src', '#include'])
+    localenv.Prepend(CPPPATH=['#src', '#include'])
 
     cantera_libname = 'cantera_shared' if os.name=='nt' else 'cantera'
     #pylinklibs = [cantera_libname, 'cvode', 'ctmath', 'ctlapack', 'ctblas', 'ctf2c', 'execstream']
diff --git a/test/SConscript b/test/SConscript
index dbdc0ac6e..c6b4fb8aa 100644
--- a/test/SConscript
+++ b/test/SConscript
@@ -4,9 +4,9 @@ import subprocess
 Import('env','build','install')
 localenv = env.Clone()
 
-localenv.Append(CPPPATH=['#ext/gtest/include', '#include'],
-                LIBPATH='#build/lib',
-                LIBS=['gtest'] + localenv['cantera_libs'])
+localenv.Prepend(CPPPATH=['#ext/gtest/include', '#include'],
+                 LIBPATH='#build/lib')
+localenv.Append(LIBS=['gtest'] + localenv['cantera_libs'])
 
 localenv['ENV']['PYTHONPATH'] = Dir('#interfaces/python').abspath
 localenv['ENV']['CANTERA_DATA'] = Dir('#data/inputs').abspath
diff --git a/test_problems/SConscript b/test_problems/SConscript
index fe1539f81..2eb081bb7 100644
--- a/test_problems/SConscript
+++ b/test_problems/SConscript
@@ -2,7 +2,7 @@ from buildutils import *
 
 Import('env','build','install')
 localenv = env.Clone()
-localenv.Append(CPPPATH=['#include', '#src', 'shared'])
+localenv.Prepend(CPPPATH=['#include', '#src', 'shared'])
 
 os.environ['PYTHONPATH'] = pjoin(os.getcwd(), '..', 'interfaces', 'python')
 os.environ['CANTERA_DATA'] = pjoin(os.getcwd(), '..', 'data', 'inputs')