diff --git a/buildbot/osuosl/master/config/builders.py b/buildbot/osuosl/master/config/builders.py
--- a/buildbot/osuosl/master/config/builders.py
+++ b/buildbot/osuosl/master/config/builders.py
@@ -362,7 +362,6 @@
                 clean=False,
                 useTwoStage=True,
                 runTestSuite=True,
-                enable_runtimes="auto",
                 testsuite_flags=[
                     '--cppflags', '-mcpu=cortex-a57 -fuse-ld=lld',
                     '--threads=32', '--build-threads=32'],
@@ -397,7 +396,6 @@
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     testsuite_flags=[
                         '--cppflags', '-mcpu=cortex-a15 -mfpu=vfpv3 -marm',
                         '--threads=4', '--build-threads=4'],
@@ -417,7 +415,6 @@
                     testStage1=False,
                     useTwoStage=True,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     testsuite_flags=[
                         '--cppflags', '-mcpu=cortex-a15 -mthumb',
                         '--threads=4', '--build-threads=4'],
@@ -436,7 +433,6 @@
     'builddir': "clang-armv8-lld-2stage",
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     clean=False,
-                    enable_runtimes="auto",
                     useTwoStage=True,
                     runTestSuite=True,
                     testsuite_flags=[
@@ -459,7 +455,6 @@
                     clean=False,
                     checkout_flang=True,
                     checkout_lld=False,
-                    enable_runtimes="auto",
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
@@ -489,7 +484,6 @@
                     clean=False,
                     checkout_flang=True,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     env={
                         'NO_STOP_MESSAGE':'1', # For Fortran test-suite
                     },
@@ -515,7 +509,6 @@
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     env={
                         'NO_STOP_MESSAGE':'1', # For Fortran test-suite
                     },
@@ -537,7 +530,6 @@
                     clean=False,
                     checkout_flang=True,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     env={
                         'NO_STOP_MESSAGE':'1', # For Fortran test-suite
                     },
@@ -563,7 +555,6 @@
                     useTwoStage=True,
                     testStage1=False,
                     runTestSuite=True,
-                    enable_runtimes="auto",
                     env={
                         'NO_STOP_MESSAGE':'1', # For Fortran test-suite
                     },
@@ -583,7 +574,6 @@
     'factory' : ClangBuilder.getClangCMakeBuildFactory(
                     vs="manual",
                     useTwoStage=True,
-                    enable_runtimes="auto",
                     checkout_flang=True,
                     extra_cmake_args=[
                         "-DCMAKE_TRY_COMPILE_CONFIGURATION=Release",
@@ -669,7 +659,6 @@
                     checks=['check-all', 'check-runtimes'],
                     checkout_lld=False,
                     useTwoStage=True,
-                    enable_runtimes="auto",
                     stage1_config='Release',
                     stage2_config='Release',
                     extra_cmake_args=[
@@ -699,7 +688,6 @@
                     checks=['check-all', 'check-runtimes'],
                     checkout_lld=False,
                     useTwoStage=True,
-                    enable_runtimes="auto",
                     stage1_config='Release',
                     stage2_config='Release',
                     extra_cmake_args=[
@@ -753,7 +741,6 @@
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
-                    enable_runtimes="auto",
                     useTwoStage=False,
                     stage1_config='Release',
                     extra_cmake_args=[
@@ -769,7 +756,6 @@
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
-                    enable_runtimes="auto",
                     useTwoStage=True,
                     stage1_config='Release',
                     stage2_config='Release',
@@ -785,7 +771,6 @@
                     jobs=4,
                     clean=False,
                     checkout_lld=False,
-                    enable_runtimes="auto",
                     useTwoStage=False,
                     runTestSuite=True,
                     stage1_config='Release',
diff --git a/zorg/buildbot/builders/ClangBuilder.py b/zorg/buildbot/builders/ClangBuilder.py
--- a/zorg/buildbot/builders/ClangBuilder.py
+++ b/zorg/buildbot/builders/ClangBuilder.py
@@ -168,7 +168,7 @@
             checkout_flang=False,
             checkout_test_suite=False,
 
-            enable_runtimes=None):
+            enable_runtimes="auto"):
     return _getClangCMakeBuildFactory(
                clean=clean, checks=checks, cmake=cmake, jobs=jobs, vs=vs,
                vs_target_arch=vs_target_arch, useTwoStage=useTwoStage,
@@ -221,7 +221,7 @@
             checkout_test_suite=False,
             checkout_flang=False,
 
-            enable_runtimes=None,
+            enable_runtimes="auto",
 
             # Upload artifacts to Google Cloud Storage (for the llvmbisect tool)
             stage1_upload_directory=None,