diff --git a/src/include/unit.h b/src/include/unit.h
index 5e4073a48..0c5dcfbf4 100644
--- a/src/include/unit.h
+++ b/src/include/unit.h
@@ -472,6 +472,7 @@ struct _unit_ {
     unsigned	Constructed : 1;	/// unit is in construction
     unsigned	Active : 1;		/// unit is active for AI
 
+#define MaxMana	255			/// maximal mana for units
     unsigned	Mana : 8;		/// mana points
     unsigned	HP;			/// hit points
     unsigned	XP;			/// experience points
diff --git a/src/unit/unit.cpp b/src/unit/unit.cpp
index 9b477aa72..51063c739 100644
--- a/src/unit/unit.cpp
+++ b/src/unit/unit.cpp
@@ -1240,7 +1240,7 @@ global void UnitIncrementMana(void)
 	    --unit->Blink;
 	}
 
-	if( unit->Type->CanCastSpell && unit->Mana!=255 ) {
+	if( unit->Type->CanCastSpell && unit->Mana!=MaxMana ) {
 	    unit->Mana++;
 
 	    // some frames delayed done my color cycling
diff --git a/src/unit/unit_draw.cpp b/src/unit/unit_draw.cpp
index dc6313d24..b574a4f4f 100644
--- a/src/unit/unit_draw.cpp
+++ b/src/unit/unit_draw.cpp
@@ -673,8 +673,8 @@ local void DrawDecoration(const Unit* unit,const UnitType* type,int x,int y)
     //	Mana bar on right side of unit. FIXME: combine bar and sprite
     //
     if( ShowManaBar ) {
-	if( type->CanCastSpell && !(ShowNoFull && unit->Mana==255) ) {
-	    DrawManaBar(x,y,type,255,unit->Mana);
+	if( type->CanCastSpell && !(ShowNoFull && unit->Mana==MaxMana) ) {
+	    DrawManaBar(x,y,type,MaxMana,unit->Mana);
 	} else if( type->GivesOil || type->GoldMine || type->OilPatch ) {
 	    DrawManaBar(x,y,type,655350,unit->Value);
 	}
@@ -736,8 +736,8 @@ local void DrawDecoration(const Unit* unit,const UnitType* type,int x,int y)
     //	Mana dot on right side of unit.
     //
     if( ShowManaDot ) {
-	if( type->CanCastSpell && !(ShowNoFull && unit->Mana==255) ) {
-	    DrawManaSprite(x,y,type,255,unit->Mana);
+	if( type->CanCastSpell && !(ShowNoFull && unit->Mana==MaxMana) ) {
+	    DrawManaSprite(x,y,type,MaxMana,unit->Mana);
 	} else if( type->GivesOil || type->GoldMine || type->OilPatch ) {
 	    DrawManaSprite(x,y,type,655350,unit->Value);
 	}