diff --git a/src/intdisplay.c b/src/intdisplay.c
index ceac4ac6f..96f3ad821 100644
--- a/src/intdisplay.c
+++ b/src/intdisplay.c
@@ -419,7 +419,7 @@ void intAddProdQuantity(WIDGET *psWidget, W_CONTEXT *psContext)
 		DROID_TEMPLATE	*psTemplate = (DROID_TEMPLATE *)psStat;
 		STRUCTURE	*psStructure = NULL;
 		BASE_OBJECT	*psObj = getCurrentSelected();
-		UDWORD		quantity = 0;
+		UDWORD		quantity = 0, remaining = 0;
 
 		if (psObj != NULL && psObj->type == OBJ_STRUCTURE && !isDead(psObj))
 		{
@@ -431,6 +431,16 @@ void intAddProdQuantity(WIDGET *psWidget, W_CONTEXT *psContext)
 		    quantity = getProductionQuantity(psStructure, psTemplate);
 		}
 
+		// now find out how many we have built
+		remaining = getProductionBuilt(psStructure, psTemplate);
+		if (quantity > remaining)
+		{
+			quantity -= remaining;
+		}
+		else
+		{
+			quantity = 0;
+		}
 		if (quantity != 0)
 		{
 			snprintf(Label->aText, sizeof(Label->aText), "%u", quantity);
diff --git a/src/structure.c b/src/structure.c
index b14cb5864..ded148bc7 100644
--- a/src/structure.c
+++ b/src/structure.c
@@ -6814,6 +6814,7 @@ void factoryProdAdjust(STRUCTURE *psStructure, DROID_TEMPLATE *psTemplate, BOOL
 	UDWORD		inc, factoryType, factoryInc;
 	FACTORY		*psFactory;
 	BOOL		bAssigned = FALSE, bCheckForCancel = FALSE;
+	UBYTE	built, quantity, remaining;
 
 	CHECK_STRUCTURE(psStructure);
 	ASSERT( psStructure->player == productionPlayer,
@@ -6828,11 +6829,15 @@ void factoryProdAdjust(STRUCTURE *psStructure, DROID_TEMPLATE *psTemplate, BOOL
 	{
 		if (asProductionRun[factoryType][factoryInc][inc].psTemplate == psTemplate)
 		{
-			//adjust the prod run
-			if (add)
+			//adjust the prod run 
+			if (add)	//user left clicked, so increase # in queue
 			{
-				asProductionRun[factoryType][factoryInc][inc].quantity++;
-				if (asProductionRun[factoryType][factoryInc][inc].quantity > MAX_IN_RUN)
+				// Allows us to queue up more units up to MAX_IN_RUN instead of ignoring how many we have built from that queue 
+				quantity = ++asProductionRun[factoryType][factoryInc][inc].quantity;
+				built = asProductionRun[factoryType][factoryInc][inc].built;
+				remaining = quantity - built;
+				// check to see if user canceled all orders in queue
+				if (remaining > MAX_IN_RUN)
 				{
 					asProductionRun[factoryType][factoryInc][inc].quantity = 0;
 					//initialise the template
@@ -6847,7 +6852,7 @@ void factoryProdAdjust(STRUCTURE *psStructure, DROID_TEMPLATE *psTemplate, BOOL
 					}
 				}
 			}
-			else
+			else	//user right clicked, so we subtract form queue
 			{
 				if (asProductionRun[factoryType][factoryInc][inc].quantity == 0)
 				{