diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -6437,7 +6437,7 @@
     handleAMDGPUCodeObjectVersionOptions(D, Args, CmdArgs);
 
     if (Args.hasFlag(options::OPT_munsafe_fp_atomics,
-                     options::OPT_mno_unsafe_fp_atomics))
+                     options::OPT_mno_unsafe_fp_atomics, /*Default=*/false))
       CmdArgs.push_back("-munsafe-fp-atomics");
   }
 
diff --git a/clang/test/Driver/hip-options.hip b/clang/test/Driver/hip-options.hip
--- a/clang/test/Driver/hip-options.hip
+++ b/clang/test/Driver/hip-options.hip
@@ -36,6 +36,10 @@
 // RUN:   --cuda-gpu-arch=gfx906  %s 2>&1 | FileCheck -check-prefix=UNSAFE-FP-ATOMICS %s
 // UNSAFE-FP-ATOMICS: clang{{.*}} "-triple" "amdgcn-amd-amdhsa" {{.*}} "-munsafe-fp-atomics"
 
+// RUN: %clang -### -nogpuinc -nogpulib \
+// RUN:   --cuda-gpu-arch=gfx906  %s 2>&1 | FileCheck -check-prefix=DEFAULT-UNSAFE-FP-ATOMICS %s
+// DEFAULT-UNSAFE-FP-ATOMICS-NOT: clang{{.*}} "-triple" "amdgcn-amd-amdhsa" {{.*}} "-munsafe-fp-atomics"
+
 // RUN: %clang -### -target x86_64-unknown-linux-gnu -nogpuinc -nogpulib -fgpu-exclude-wrong-side-overloads \
 // RUN:   --cuda-gpu-arch=gfx906  %s 2>&1 | FileCheck -check-prefix=FIX-OVERLOAD %s
 // FIX-OVERLOAD: clang{{.*}} "-triple" "amdgcn-amd-amdhsa" {{.*}} "-fgpu-exclude-wrong-side-overloads" "-fgpu-defer-diag"