diff --git a/src/fheroes2/game/difficulty.cpp b/src/fheroes2/game/difficulty.cpp
index cd28051b47e..f3f3e06a504 100644
--- a/src/fheroes2/game/difficulty.cpp
+++ b/src/fheroes2/game/difficulty.cpp
@@ -124,11 +124,11 @@ Funds Difficulty::getResourceIncomeBonusForAI( const int difficulty, const VecCa
 
     switch ( difficulty ) {
     case Difficulty::HARD:
-        return getIncomeFromSetsOfResourceMines( Resource::ORE | Resource::WOOD | Resource::GOLD, 1 );
+        return getIncomeFromSetsOfResourceMines( Resource::GOLD, 1 );
     case Difficulty::EXPERT:
-        return getIncomeFromSetsOfResourceMines( Resource::ORE | Resource::WOOD | Resource::GOLD, 1 ) + getBonusForCastles();
+        return getIncomeFromSetsOfResourceMines( Resource::GOLD, 1 ) + getBonusForCastles();
     case Difficulty::IMPOSSIBLE:
-        return getIncomeFromSetsOfResourceMines( Resource::ALL, 1 ) + getBonusForCastles();
+        return getIncomeFromSetsOfResourceMines( Resource::GOLD, 2 ) + getBonusForCastles();
     default:
         break;
     }