diff --git a/cpu.cpp b/cpu.cpp
index 03c74d9..43111c9 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -289,6 +289,8 @@ void cpu::queue_interrupt(const uint8_t level, const uint8_t vector)
 
 	it->second.insert(vector);
 
+	qi_cv.notify_all();
+
 	DOLOG(debug, true, "Queueing interrupt vector %o (IPL %d, current: %d), n: %zu", vector, level, getPSW_spl(), it->second.size());
 }
 
@@ -1485,6 +1487,14 @@ bool cpu::misc_operations(const uint16_t instr)
 			return true;
 
 		case 0b0000000000000001: // WAIT
+			{
+				std::unique_lock<std::mutex> lck(qi_lock);
+
+				qi_cv.wait(lck);
+			}
+
+			DOLOG(debug, false, "WAIT returned");
+
 			return true;
 
 		case 0b0000000000000010: // RTI
diff --git a/cpu.h b/cpu.h
index 11163ae..6eca542 100644
--- a/cpu.h
+++ b/cpu.h
@@ -1,8 +1,9 @@
-// (C) 2018-2022 by Folkert van Heusden
+// (C) 2018-2023 by Folkert van Heusden
 // Released under Apache License v2.0
 #pragma once
 
 #include <assert.h>
+#include <condition_variable>
 #include <map>
 #include <mutex>
 #include <optional>
@@ -39,7 +40,8 @@ private:
 
 	// level, vector
 	std::map<uint8_t, std::set<uint8_t> > queued_interrupts;
-	std::mutex qi_lock;
+	std::mutex              qi_lock;
+	std::condition_variable qi_cv;
 
 	std::set<uint16_t> breakpoints;