diff --git a/SConstruct b/SConstruct
index abd5e9022c..6bb23ce09d 100644
--- a/SConstruct
+++ b/SConstruct
@@ -450,6 +450,7 @@ def BuildSpecific(env, mode, env_overrides):
   for sample in context.samples:
     sample_env = Environment(LIBRARY=library_name)
     sample_env.Replace(**context.flags['sample'])
+    sample_env['ENV'].update(**context.env_overrides)
     sample_object = sample_env.SConscript(
       join('samples', 'SConscript'),
       build_dir=join('obj', 'sample', sample, target_id),
diff --git a/test/cctest/SConscript b/test/cctest/SConscript
index 2da4de62f2..cc59199148 100644
--- a/test/cctest/SConscript
+++ b/test/cctest/SConscript
@@ -53,6 +53,7 @@ def Build():
   cctest_files = context.GetRelevantSources(SOURCES)
   env = Environment()
   env.Replace(**context.flags['cctest'])
+  env['ENV'].update(**context.env_overrides)
   # There seems to be a glitch in the way scons decides where to put
   # PDB files when compiling using MSVC so we specify it manually.
   # This should not affect any other platforms.
diff --git a/tools/test.py b/tools/test.py
index 5a7e331d1e..ef47a381bc 100755
--- a/tools/test.py
+++ b/tools/test.py
@@ -490,8 +490,10 @@ def RunTestCases(all_cases, progress):
   return progress.Run()
 
 
-def BuildRequirements(context, requirements, mode):
-  command_line = ['scons', '-Y', context.workspace, 'mode=' + ",".join(mode)] + requirements
+def BuildRequirements(context, requirements, mode, scons_flags):
+  command_line = (['scons', '-Y', context.workspace, 'mode=' + ",".join(mode)]
+                  + requirements
+                  + scons_flags)
   output = ExecuteNoCapture(command_line, context)
   return output.exit_code == 0
 
@@ -921,6 +923,8 @@ def BuildOptions():
       default='release')
   result.add_option("-v", "--verbose", help="Verbose output",
       default=False, action="store_true")
+  result.add_option("-S", dest="scons_flags", help="Flag to pass through to scons",
+      default=[], action="append")
   result.add_option("-p", "--progress",
       help="The style of progress indicator (verbose, dots, color, mono)",
       choices=PROGRESS_INDICATORS.keys(), default="mono")
@@ -1026,7 +1030,7 @@ def Main():
       reqs += root.GetBuildRequirements(path, context)
     reqs = list(set(reqs))
     if len(reqs) > 0:
-      if not BuildRequirements(context, reqs, options.mode):
+      if not BuildRequirements(context, reqs, options.mode, options.scons_flags):
         return 1
 
   # Get status for tests