diff --git a/src/info.cpp b/src/info.cpp
index a513f67aff..c4be50d47f 100644
--- a/src/info.cpp
+++ b/src/info.cpp
@@ -131,6 +131,10 @@ void FState::CheckCallerType(AActor *self, AActor *stateowner)
 			ThrowAbortException(X_OTHER, "Bad function prototype in function call to %s", ActionFunc->PrintableName.GetChars());
 		}
 		auto cls = static_cast<PObjectPointer*>(requiredType)->PointedClass();
+		if (check == nullptr)
+		{
+			ThrowAbortException(X_OTHER, "%s called without valid caller. %s expected", ActionFunc->PrintableName.GetChars(), cls->TypeName.GetChars());
+		}
 		if (!check->IsKindOf(cls))
 		{
 			ThrowAbortException(X_OTHER, "Invalid class %s in function call to %s. %s expected", check->GetClass()->TypeName.GetChars(), ActionFunc->PrintableName.GetChars(), cls->TypeName.GetChars());
@@ -223,6 +227,10 @@ bool FState::CallAction(AActor *self, AActor *stateowner, FStateParamInfo *info,
 				}
 				err.stacktrace.AppendFormat("Called from %sstate %s in %s\n", callinfo, FState::StaticGetStateName(this).GetChars(), stateowner->GetClass()->TypeName.GetChars());
 			}
+			else
+			{
+				err.stacktrace.AppendFormat("Called from state %s\n", FState::StaticGetStateName(this).GetChars());
+			}
 
 			throw;
 		}
diff --git a/wadsrc/static/zscript/shared/player.txt b/wadsrc/static/zscript/shared/player.txt
index c4fa074843..b56a60a543 100644
--- a/wadsrc/static/zscript/shared/player.txt
+++ b/wadsrc/static/zscript/shared/player.txt
@@ -2256,7 +2256,7 @@ class PSprite : Object native play
 				Tics--;
 				// [BC] Apply double firing speed.
 				if (bPowDouble && Tics && (Owner.mo.FindInventory ("PowerDoubleFiringSpeed", true))) Tics--;
-				if (!Tics) SetState(CurState.NextState);
+				if (!Tics && Caller != null) SetState(CurState.NextState);
 			}
 		}
 	}