diff --git a/src/gamedata/d_dehacked.cpp b/src/gamedata/d_dehacked.cpp
index 7ed171374..cf8e8ea7a 100644
--- a/src/gamedata/d_dehacked.cpp
+++ b/src/gamedata/d_dehacked.cpp
@@ -237,7 +237,7 @@ static AmmoPerAttack AmmoPerAttacks[] = {
 	{ NAME_A_FireBFG, -1},	// uses deh.BFGCells
 	{ NAME_A_FireOldBFG, 1},
 	{ NAME_A_FireRailgun, 1},
-	{ NAME_A_ConsumeAmmo, 1}, // MBF21
+	{ NAME_MBF21_ConsumeAmmo, 1}, // MBF21
 	{ NAME_None, 0}
 };
 
@@ -3587,8 +3587,9 @@ void FinishDehPatch ()
 					{
 						auto p = dyn_cast<PFunction>(wcls->FindSymbol(AmmoPerAttacks[j].func, true));
 						if (p != nullptr) AmmoPerAttacks[j].ptr = p->Variants[0].Implementation;
+						assert(AmmoPerAttacks[j].ptr);
 					}
-					if (state->ActionFunc == AmmoPerAttacks[j].ptr)
+					if (state->ActionFunc == AmmoPerAttacks[j].ptr && AmmoPerAttacks[j].ptr)
 					{
 						found = true;
 						int use = AmmoPerAttacks[j].ammocount;
diff --git a/src/namedef_custom.h b/src/namedef_custom.h
index 1ca25a1f1..6f7bcbc78 100644
--- a/src/namedef_custom.h
+++ b/src/namedef_custom.h
@@ -233,7 +233,7 @@ xx(A_FirePlasma)
 xx(A_FireBFG)
 xx(A_FireOldBFG)
 xx(A_FireRailgun)
-xx(A_ConsumeAmmo)
+xx(MBF21_ConsumeAmmo)
 
 // Special translation names
 xx(RainPillar1)