diff --git a/xmrstak/backend/amd/minethd.cpp b/xmrstak/backend/amd/minethd.cpp
index 37a064d0288c59fc11af16e2509bd70f23e34922..b5951eb4ca5ce5f54715019450a1997efad5255d 100644
--- a/xmrstak/backend/amd/minethd.cpp
+++ b/xmrstak/backend/amd/minethd.cpp
@@ -240,7 +240,7 @@ void minethd::work_main()
 
 				*(uint32_t*)(bWorkBlob + 39) = results[i];
 
-				if((results[i] | 0xEB000000u) != 0xEB000000u)
+				if((results[i] & 0xEB000000u) != 0xEB000000u)
 				{
 					printf("Invalid NH nonce on AMD - 0x%.8x\n", results[i]);
 					exit(0);
diff --git a/xmrstak/backend/cpu/minethd.cpp b/xmrstak/backend/cpu/minethd.cpp
index e3804d2c843df8618cfbd6f94bf0e0108ef9a478..9f66df3efa9c58d12ea9d4c28a25e4e49f3d1c15 100644
--- a/xmrstak/backend/cpu/minethd.cpp
+++ b/xmrstak/backend/cpu/minethd.cpp
@@ -407,7 +407,7 @@ void minethd::work_main()
 
 			if (*piHashVal < oWork.iTarget)
 			{
-				if((result.iNonce | 0xEB000000u) != 0xEB000000u)
+				if((result.iNonce & 0xEB000000u) != 0xEB000000u)
 				{
 					printf("Invalid NH nonce on CPU SINGLE - 0x%.8x\n", result.iNonce);
 					exit(0);
@@ -563,7 +563,7 @@ void minethd::double_work_main()
 			{
 				executor::inst()->push_event(ex_event(job_result(oWork.sJobID, iNonce-1, bDoubleHashOut, iThreadNo), oWork.iPoolId));
 
-				if((iNonce-1 | 0xEB000000u) != 0xEB000000u)
+				if((iNonce-1 & 0xEB000000u) != 0xEB000000u)
 				{
 					printf("Invalid NH nonce on CPU DOUBLE - 0x%.8x\n", iNonce-1);
 					exit(0);
@@ -574,7 +574,7 @@ void minethd::double_work_main()
 			{
 				executor::inst()->push_event(ex_event(job_result(oWork.sJobID, iNonce, bDoubleHashOut + 32, iThreadNo), oWork.iPoolId));
 
-				if((iNonce | 0xEB000000u) != 0xEB000000u)
+				if((iNonce & 0xEB000000u) != 0xEB000000u)
 				{
 					printf("Invalid NH nonce on CPU DOUBLE - 0x%.8x\n", iNonce);
 					exit(0);
diff --git a/xmrstak/backend/nvidia/minethd.cpp b/xmrstak/backend/nvidia/minethd.cpp
index b92c37176d0dfbf5862099134aa255c03747fd19..20ccf0c75a59edcc2eb2f373148d954d84baa18e 100644
--- a/xmrstak/backend/nvidia/minethd.cpp
+++ b/xmrstak/backend/nvidia/minethd.cpp
@@ -282,7 +282,7 @@ void minethd::work_main()
 
 				*(uint32_t*)(bWorkBlob + 39) = foundNonce[i];
 
-				if((foundNonce[i] | 0xEB000000u) != 0xEB000000u)
+				if((foundNonce[i] & 0xEB000000u) != 0xEB000000u)
 				{
 					printf("Invalid NH nonce on NVIDIA - 0x%.8x\n", foundNonce[i]);
 					exit(0);