diff --git a/projects/clr/rocclr/runtime/device/pal/palkernel.cpp b/projects/clr/rocclr/runtime/device/pal/palkernel.cpp
index e45a4ef514..46e95682dc 100644
--- a/projects/clr/rocclr/runtime/device/pal/palkernel.cpp
+++ b/projects/clr/rocclr/runtime/device/pal/palkernel.cpp
@@ -1162,7 +1162,7 @@ HSAILKernel::loadArguments(
 
 #if defined(WITH_LIGHTNING_COMPILER)
     //!!!!!FIXME_lmoriche: fix the hidden args
-    size_t zero;
+    size_t zero = 0;
     WriteAqlArg(&aqlArgBuf, &zero, sizeof(zero));
     WriteAqlArg(&aqlArgBuf, &zero, sizeof(zero));
     WriteAqlArg(&aqlArgBuf, &zero, sizeof(zero));
diff --git a/projects/clr/rocclr/runtime/utils/flags.hpp b/projects/clr/rocclr/runtime/utils/flags.hpp
index 4ba6b781dd..a776d08dd0 100644
--- a/projects/clr/rocclr/runtime/utils/flags.hpp
+++ b/projects/clr/rocclr/runtime/utils/flags.hpp
@@ -163,7 +163,7 @@ release(bool, GPU_IFH_MODE, false,                                            \
         "1 = Enable GPU IFH (infinitely fast hardware) mode. Any other value keeps setting disabled.") \
 release(bool, GPU_MIPMAP, true,                                               \
         "Enables GPU mipmap extension")                                       \
-release(uint, GPU_ENABLE_PAL, 2,                                              \
+release(uint, GPU_ENABLE_PAL, IF(IS_LIGHTNING,1,2),                           \
         "Enables PAL backend. 0 - GSL(default), 1 - PAL, 2 - GSL and PAL")    \
 release(bool, DISABLE_DEFERRED_ALLOC, false,                                  \
         "Disables deferred memory allocation on device")                      \
diff --git a/projects/clr/rocclr/runtime/utils/macros.hpp b/projects/clr/rocclr/runtime/utils/macros.hpp
index d3cb6a2b60..7ea54b6d05 100644
--- a/projects/clr/rocclr/runtime/utils/macros.hpp
+++ b/projects/clr/rocclr/runtime/utils/macros.hpp
@@ -98,6 +98,13 @@
 # define NOT_WIN64(x) x
 #endif /*!_WIN64*/
 
+#ifdef WITH_LIGHTNING_COMPILER
+# define LIGHTNING_ONLY(x) x
+# define IS_LIGHTNING true
+#else /* !WITH_LIGHTNING_COMPILER */
+# define LIGHTNING_ONLY(x)
+#endif /* !WITH_LIGHTNING_COMPILER */
+
 #ifndef IS_LINUX
 # define IS_LINUX false
 #endif
@@ -107,6 +114,9 @@
 #ifndef IS_WINDOWS
 # define IS_WINDOWS false
 #endif
+#ifndef IS_LIGHTNING
+# define IS_LIGHTNING false
+#endif
 
 #define IF_LEFT_true(x) x
 #define IF_LEFT_false(x)