diff --git a/test/Driver/filelists.swift b/test/Driver/filelists.swift
index c6201c8b223fd..72301790d08c1 100644
--- a/test/Driver/filelists.swift
+++ b/test/Driver/filelists.swift
@@ -56,12 +56,12 @@
 // CHECK-WMO-THREADED-NOT: Handled
 
 // RUN: mkdir -p %t/tmp-fail/
-// RUN: (cd %t && not env TMPDIR="%t/tmp-fail/" %swiftc_driver_plain -driver-use-frontend-path %S/Inputs/fail.py -c ./a.swift ./b.swift ./c.swift -module-name main -target x86_64-apple-macosx10.9 -driver-filelist-threshold=0 -output-file-map=%S/Inputs/filelists/output.json -force-single-frontend-invocation -num-threads 1)
+// RUN: (cd %t && env TMPDIR="%t/tmp-fail/" not %swiftc_driver_plain -driver-use-frontend-path %S/Inputs/fail.py -c ./a.swift ./b.swift ./c.swift -module-name main -target x86_64-apple-macosx10.9 -driver-filelist-threshold=0 -output-file-map=%S/Inputs/filelists/output.json -force-single-frontend-invocation -num-threads 1)
 // RUN: not ls %t/tmp-fail/sources-*
 // RUN: not ls %t/tmp-fail/outputs-*
 
 // RUN: mkdir -p %t/tmp-crash/
-// RUN: (cd %t && not env TMPDIR="%t/tmp-crash/" %swiftc_driver_plain -driver-use-frontend-path %S/Inputs/crash.py -c ./a.swift ./b.swift ./c.swift -module-name main -target x86_64-apple-macosx10.9 -driver-filelist-threshold=0 -output-file-map=%S/Inputs/filelists/output.json -force-single-frontend-invocation -num-threads 1)
+// RUN: (cd %t && env TMPDIR="%t/tmp-crash/" not %swiftc_driver_plain -driver-use-frontend-path %S/Inputs/crash.py -c ./a.swift ./b.swift ./c.swift -module-name main -target x86_64-apple-macosx10.9 -driver-filelist-threshold=0 -output-file-map=%S/Inputs/filelists/output.json -force-single-frontend-invocation -num-threads 1)
 // RUN: ls %t/tmp-crash/sources-* %t/tmp-crash/outputs-*
 
 
diff --git a/test/Sanitizers/asan.swift b/test/Sanitizers/asan.swift
index 68334f638b9de..d0849da3128e3 100644
--- a/test/Sanitizers/asan.swift
+++ b/test/Sanitizers/asan.swift
@@ -1,6 +1,6 @@
 // RUN: %target-swiftc_driver %s -target %sanitizers-target-triple -g -sanitize=address -o %t_asan-binary
 // RUN: %target-codesign %t_asan-binary
-// RUN: not env %env-ASAN_OPTIONS=abort_on_error=0 %target-run %t_asan-binary 2>&1 | %FileCheck %s
+// RUN: env %env-ASAN_OPTIONS=abort_on_error=0 not %target-run %t_asan-binary 2>&1 | %FileCheck %s
 // REQUIRES: executable_test
 // REQUIRES: asan_runtime
 
diff --git a/test/Sanitizers/asan_recover.swift b/test/Sanitizers/asan_recover.swift
index dbb8bd7662b68..b65c977b68aeb 100644
--- a/test/Sanitizers/asan_recover.swift
+++ b/test/Sanitizers/asan_recover.swift
@@ -12,14 +12,14 @@
 // RUN: %FileCheck --check-prefixes=CHECK-COMMON-STDOUT,CHECK-RECOVER-STDOUT -input-file=%t_asan_recover.stdout %s
 
 // Check with recovery instrumentation but without runtime option to continue execution.
-// RUN: not env %env-ASAN_OPTIONS=abort_on_error=0,halt_on_error=1 %target-run %t_asan_recover > %t_asan_no_runtime_recover.stdout 2> %t_asan_no_runtime_recover.stderr
+// RUN: env %env-ASAN_OPTIONS=abort_on_error=0,halt_on_error=1 not %target-run %t_asan_recover > %t_asan_no_runtime_recover.stdout 2> %t_asan_no_runtime_recover.stderr
 // RUN: %FileCheck --check-prefixes=CHECK-COMMON-STDERR -input-file=%t_asan_no_runtime_recover.stderr %s
 // RUN: %FileCheck --check-prefixes=CHECK-COMMON-STDOUT,CHECK-NO-RECOVER-STDOUT -input-file=%t_asan_no_runtime_recover.stdout %s
 
 // Check that without recovery instrumentation and runtime option to continue execution that error recovery does not happen.
 // RUN: %target-swiftc_driver %s -target %sanitizers-target-triple -g -sanitize=address -import-objc-header %S/asan_interface.h -o %t_asan_no_recover
 // RUN: %target-codesign %t_asan_no_recover
-// RUN: not env %env-ASAN_OPTIONS=abort_on_error=0,halt_on_error=0 %target-run %t_asan_no_recover > %t_asan_no_recover.stdout 2> %t_asan_no_recover.stderr
+// RUN: env %env-ASAN_OPTIONS=abort_on_error=0,halt_on_error=0 not %target-run %t_asan_no_recover > %t_asan_no_recover.stdout 2> %t_asan_no_recover.stderr
 // RUN: %FileCheck --check-prefixes=CHECK-COMMON-STDERR -input-file=%t_asan_no_recover.stderr %s
 // RUN: %FileCheck --check-prefixes=CHECK-COMMON-STDOUT,CHECK-NO-RECOVER-STDOUT -input-file=%t_asan_no_recover.stdout %s
 
diff --git a/test/Sanitizers/tsan-libdispatch.swift b/test/Sanitizers/tsan-libdispatch.swift
index 7df6a1d0da99a..4739735da8795 100644
--- a/test/Sanitizers/tsan-libdispatch.swift
+++ b/test/Sanitizers/tsan-libdispatch.swift
@@ -1,6 +1,6 @@
 // RUN: %target-swiftc_driver %s -g -sanitize=thread %import-libdispatch -o %t_tsan-binary
 // RUN: %target-codesign %t_tsan-binary
-// RUN: not env %env-TSAN_OPTIONS=abort_on_error=0 %target-run %t_tsan-binary 2>&1 | %FileCheck %s
+// RUN: env %env-TSAN_OPTIONS=abort_on_error=0 not %target-run %t_tsan-binary 2>&1 | %FileCheck %s
 // REQUIRES: executable_test
 // REQUIRES: tsan_runtime
 // UNSUPPORTED: OS=tvos
diff --git a/test/Sanitizers/tsan.swift b/test/Sanitizers/tsan.swift
index efb3ef954d305..e7f72ed918237 100644
--- a/test/Sanitizers/tsan.swift
+++ b/test/Sanitizers/tsan.swift
@@ -1,6 +1,6 @@
 // RUN: %target-swiftc_driver %s -target %sanitizers-target-triple -g -sanitize=thread %import-libdispatch -o %t_tsan-binary
 // RUN: %target-codesign %t_tsan-binary
-// RUN: not env %env-TSAN_OPTIONS="abort_on_error=0" %target-run %t_tsan-binary 2>&1 | %FileCheck %s
+// RUN: env %env-TSAN_OPTIONS="abort_on_error=0" not %target-run %t_tsan-binary 2>&1 | %FileCheck %s
 // REQUIRES: executable_test
 // REQUIRES: tsan_runtime
 // UNSUPPORTED: OS=tvos