diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 8da6a55593..c68270f794 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -799,8 +799,12 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
                  * raised when single-stepping so that GDB doesn't miss the
                  * next instruction.
                  */
-                cpu->exception_index =
-                    (cpu->singlestep_enabled ? EXCP_DEBUG : -1);
+                if (unlikely(cpu->singlestep_enabled)) {
+                    cpu->exception_index = EXCP_DEBUG;
+                    qemu_mutex_unlock_iothread();
+                    return true;
+                }
+                cpu->exception_index = -1;
                 *last_tb = NULL;
             }
             /* The target hook may have updated the 'cpu->interrupt_request';