diff --git a/bolt/test/runtime/X86/Inputs/basic-instrumentation.s b/bolt/test/runtime/X86/Inputs/basic-instrumentation.s
index 388d2cdbd085b..c28fa2210d256 100644
--- a/bolt/test/runtime/X86/Inputs/basic-instrumentation.s
+++ b/bolt/test/runtime/X86/Inputs/basic-instrumentation.s
@@ -1,3 +1,4 @@
+  .att_syntax
   .globl main
   .type main, %function
 main:
diff --git a/bolt/test/runtime/X86/Inputs/internalcall.S b/bolt/test/runtime/X86/Inputs/internalcall.S
index 775a67122d2d7..18f7914ef65ec 100644
--- a/bolt/test/runtime/X86/Inputs/internalcall.S
+++ b/bolt/test/runtime/X86/Inputs/internalcall.S
@@ -1,6 +1,7 @@
 // This is reduced test case for BOLT containing an internal call based on
 // GetCoreDump (from google core dumper).
 
+  .att_syntax
   .text
   .globl getCallback
   .type getCallback, %function
diff --git a/bolt/test/runtime/X86/Inputs/pie-exceptions-failed-split.s b/bolt/test/runtime/X86/Inputs/pie-exceptions-failed-split.s
index 5195d298b1bbe..fd12c26750b2c 100644
--- a/bolt/test/runtime/X86/Inputs/pie-exceptions-failed-split.s
+++ b/bolt/test/runtime/X86/Inputs/pie-exceptions-failed-split.s
@@ -49,6 +49,7 @@
 #			return !throw_test(argc, argv);
 #		}
 
+	.att_syntax
 	.text
 	.file	"exceptions-failed-split.cpp"
 	.globl	_Z3bari                         # -- Begin function _Z3bari
diff --git a/bolt/test/runtime/X86/exceptions-lpstart-zero.s b/bolt/test/runtime/X86/exceptions-lpstart-zero.s
index b487ff0fa2f59..1e377ea26cfd0 100644
--- a/bolt/test/runtime/X86/exceptions-lpstart-zero.s
+++ b/bolt/test/runtime/X86/exceptions-lpstart-zero.s
@@ -21,6 +21,7 @@
 # The exception table was modified with udata4 LPStartEncoding and sdata4
 # CallSiteEncoding.
 
+	.att_syntax
 	.text
 	.globl	main                            # -- Begin function main
 	.p2align	4, 0x90