diff --git a/QPUassembler/vc4_qpu_defines.h b/QPUassembler/vc4_qpu_defines.h
index cbd5360..fc91f7d 100644
--- a/QPUassembler/vc4_qpu_defines.h
+++ b/QPUassembler/vc4_qpu_defines.h
@@ -119,11 +119,11 @@ typedef enum {
 static const char *qpu_sig_bits_str[] = {
 		[QPU_SIG_SW_BREAKPOINT] = "sig_brk",
 		[QPU_SIG_NONE] = "sig_none",
-		[QPU_SIG_THREAD_SWITCH] = "sig_switch",
+		[QPU_SIG_THREAD_SWITCH] = "sig_thread_switch",
 		[QPU_SIG_PROG_END] = "sig_end",
 		[QPU_SIG_WAIT_FOR_SCOREBOARD] = "sig_wait_score",
 		[QPU_SIG_SCOREBOARD_UNLOCK] = "sig_unlock_score",
-		[QPU_SIG_LAST_THREAD_SWITCH] = "sig_thread_switch",
+		[QPU_SIG_LAST_THREAD_SWITCH] = "sig_last_thread_switch",
 		[QPU_SIG_COVERAGE_LOAD] = "sig_coverage_load",
 		[QPU_SIG_COLOR_LOAD] = "sig_color_load",
 		[QPU_SIG_COLOR_LOAD_END] = "sig_color_load_end",
diff --git a/driver/shader.c b/driver/shader.c
index c747b11..2175fd4 100644
--- a/driver/shader.c
+++ b/driver/shader.c
@@ -51,15 +51,16 @@ VkResult vkCreateShaderModuleFromRpiAssemblyEXT(VkDevice device, VkRpiShaderModu
 			shader->bos[c] = vc4_bo_alloc_shader(controlFd, instructions, &size);
 
 			//TODO if debug...
-			for(uint64_t c = 0; c < numInstructions; ++c)
+			for(uint64_t d = 0; d < numInstructions; ++d)
 			{
-				printf("%#llx ", instructions[c]);
-				disassemble_qpu_asm(instructions[c]);
+				printf("%#llx ", instructions[d]);
+				disassemble_qpu_asm(instructions[d]);
 			}
 
-			for(uint64_t c = 0; c < numInstructions; ++c)
+			for(uint64_t d = 0; d < numInstructions; ++d)
 			{
-				if((instructions[c] & (0xfll << 60)) == (2ll << 60))
+				uint64_t s = (instructions[d] & (0xfll << 60)) >> 60;
+				if(s == 2ll)
 				{
 					shader->hasThreadSwitch = 1;
 					break;