diff --git a/cpu.cpp b/cpu.cpp
index bb25d1f..78ec28e 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -1461,10 +1461,10 @@ void cpu::disassemble()
 		}
 
 		if ((instruction >> 8) == 0b10001000)
-			text = format("EMT %d", instruction & 255);
+			text = format("EMT %o", instruction & 255);
 
 		if ((instruction >> 8) == 0b10001001)
-			text = format("TRAP %d", instruction & 255);
+			text = format("TRAP %o", instruction & 255);
 
 		if ((instruction & ~0b111111) == 0b0000000001000000) {
 			auto dst_text = addressing_to_string(src_register, pc);