diff --git a/msccl/language/instruction_dag.py b/msccl/language/instruction_dag.py
index d099126..451ea7e 100755
--- a/msccl/language/instruction_dag.py
+++ b/msccl/language/instruction_dag.py
@@ -12,11 +12,15 @@ def remove_op(op: Op):
     for p in op.prev:
         p.next.remove(op)
         p.next += op.next
+        p.next = list(set(p.next))
 
     for n in op.next:
         n.prev.remove(op)
         n.prev = op.prev.union(n.prev)
 
+    op.next = []
+    op.prev = []
+
 
 def merge_op(op: Op, other_op: Op):
     if other_op in op.next:
@@ -34,6 +38,22 @@ def merge_op(op: Op, other_op: Op):
     op.next = list(set(op.next + other_op.next))
 
 
+def circular_dep_after_merge(op: Op, other_op: Op):
+    root = set([op, other_op])
+    frontier = set(op.next)
+    if other_op in frontier:
+        frontier.remove(other_op)
+    frontier = list(frontier.union(other_op.next))
+    while len(frontier) > 0:
+        current = frontier[0]
+        for n in current.next:
+            # The root node will be visited again if there is a circular dependency
+            if n in root:
+                return True
+            frontier.append(n)
+        frontier = frontier[1:]
+
+
 def same_tb(op1: Op, op2: Op):
     return op1.tb == op2.tb and op1.channel == op2.channel
 
diff --git a/msccl/language/mscclpp/instruction_dag.py b/msccl/language/mscclpp/instruction_dag.py
index 91964e2..65a6455 100644
--- a/msccl/language/mscclpp/instruction_dag.py
+++ b/msccl/language/mscclpp/instruction_dag.py
@@ -8,6 +8,7 @@
     buf_dst_src_match,
     merge_op,
     remove_op,
+    circular_dep_after_merge,
     same_buf_dst,
     same_buf_src,
     same_chan_type,
@@ -234,6 +235,7 @@ def _optimize_rrc_r_signal_wait(self):
                                 and same_count(op, next_op)
                                 and same_buf_dst(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 op.srcs.append(
                                     (
@@ -257,6 +259,7 @@ def _optimize_rrc_r_signal_wait(self):
                                 next_op.inst == Instruction.reduce
                                 and same_buf_dst(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 op.srcs.append(
                                     (
@@ -280,6 +283,7 @@ def _optimize_rrc_r_signal_wait(self):
                                 next_op.inst == Instruction.reduce_packet
                                 and same_buf_dst(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 op.srcs.append(
                                     (
@@ -303,6 +307,7 @@ def _optimize_rrc_r_signal_wait(self):
                                 next_op.inst == Instruction.signal
                                 and same_buf_src(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 op.dsts.append(
                                     (
@@ -334,6 +339,7 @@ def _optimize_rrc_r_signal_wait(self):
                                 next_op.inst == Instruction.wait
                                 and same_buf_dst(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 op.srcs.append(
                                     (
@@ -376,6 +382,7 @@ def _optimize_rrcs_rs(self):
                                 and same_count(op, next_op)
                                 and buf_dst_src_match(op, next_op)
                                 and same_chan_type(op, next_op)
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 if len(op.dsts) > 0 and op.dsts[0][0].buffer != next_op.dst.buffer:
                                     continue
@@ -404,6 +411,7 @@ def _optimize_rrcs_rs(self):
                                 and same_count(op, next_op)
                                 and buf_dst_src_match(op, next_op)
                                 and next_op.channel_type == ChannelType.sm
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 if len(op.dsts) > 0 and op.dsts[0][0].buffer != next_op.dst.buffer:
                                     continue
@@ -433,6 +441,7 @@ def _optimize_rrcs_rs(self):
                                 and same_count(op, next_op)
                                 and buf_dst_src_match(op, next_op)
                                 and next_op.channel_type == ChannelType.sm
+                                and not circular_dep_after_merge(op, next_op)
                             ):
                                 if len(op.dsts) > 0 and op.dsts[0][0].buffer != next_op.dst.buffer:
                                     continue
@@ -473,6 +482,7 @@ def _optimize_get_put(self):
                                 and same_src_dst_buffer_type(op, seq_op)
                                 and same_chan_type(op, seq_op)
                                 and same_count(op, seq_op)
+                                and not circular_dep_after_merge(op, seq_op)
                             ):
                                 op.dsts.append(
                                     (
@@ -501,6 +511,7 @@ def _optimize_get_put(self):
                                 and same_src_dst_buffer_type(op, seq_op)
                                 and same_chan_type(op, seq_op)
                                 and same_count(op, seq_op)
+                                and not circular_dep_after_merge(op, seq_op)
                             ):
                                 op.dsts.append(
                                     (
@@ -529,6 +540,7 @@ def _optimize_get_put(self):
                                 and same_src_dst_buffer_type(op, seq_op)
                                 and same_chan_type(op, seq_op)
                                 and same_count(op, seq_op)
+                                and not circular_dep_after_merge(op, seq_op)
                             ):
                                 op.dsts.append(
                                     (
@@ -569,6 +581,7 @@ def _parallel_signal_wait(self):
                                 seq_op.inst == Instruction.signal
                                 and same_src_dst_buffer_type(op, seq_op)
                                 and same_chan_type(op, seq_op)
+                                and not circular_dep_after_merge(op, seq_op)
                             ):
                                 op.dsts.append(
                                     (
@@ -596,6 +609,7 @@ def _parallel_signal_wait(self):
                                 seq_op.inst == Instruction.wait
                                 and same_src_dst_buffer_type(op, seq_op)
                                 and same_chan_type(op, seq_op)
+                                and not circular_dep_after_merge(op, seq_op)
                             ):
                                 op.dsts.append(
                                     (