diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Audio.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Audio.cs
index 3b94dc01de..28b9c2edf2 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Audio.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Audio.cs
@@ -552,7 +552,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					SQ1_output *= SQ1_vol_state;
 
 					// avoid aliasing at high frequenices
-					if (SQ1_frq > 0x7D2) { SQ1_output = 0; }
+					if (SQ1_frq > 0x7F0) { SQ1_output = 0; }
 				}
 			}
 
@@ -570,7 +570,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					SQ2_output *= SQ2_vol_state;
 
 					// avoid aliasing at high frequenices
-					if (SQ2_frq > 0x7D2) { SQ2_output = 0; }
+					if (SQ2_frq > 0x7F0) { SQ2_output = 0; }
 				}
 			}
 
@@ -615,6 +615,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					WAVE_output = sample;
 
 					if (!WAVE_DAC_pow) { WAVE_output = 0; }
+
+					// avoid aliasing at high frequenices
+					if (WAVE_frq > 0x7F0) { WAVE_output = 0; }
 				}
 			}
 
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/PPU.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/PPU.cs
index 626bb7f549..9b17a7d619 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/PPU.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/PPU.cs
@@ -120,6 +120,14 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					LCDC = value;
 					break; 
 				case 0xFF41: // STAT
+					// writing to STAT during mode 0 or 2 causes a STAT IRQ
+					if (LCDC.Bit(7))
+					{
+						if (((STAT & 3) == 0) || ((STAT & 3) == 1))
+						{
+							LYC_INT = true;
+						}
+					}
 					STAT = (byte)((value & 0xF8) | (STAT & 7) | 0x80);
 					break; 
 				case 0xFF42: // SCY
@@ -136,6 +144,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 				case 0xFF45:  // LYC
 					LYC = value;
 					if (LY != LYC) { STAT &= 0xFB; }
+					Console.WriteLine(value);
 					break;
 				case 0xFF46: // DMA 
 					DMA_addr = value;