diff --git a/c/reg_test/expected/out b/c/reg_test/expected/out
index fa3a44e71..9542ac544 100644
--- a/c/reg_test/expected/out
+++ b/c/reg_test/expected/out
@@ -14567,6 +14567,67 @@ a=wye,variable.name=0.777892
 a=zee,variable.name=1.125680
 a=hat,variable.name=0.031442
 
+mlr put for (k,v in $*) { if (k == "i") {unset $[k]}} ./reg_test/input/abixy
+a=pan,b=pan,x=0.3467901443380824,y=0.7268028627434533
+a=eks,b=pan,x=0.7586799647899636,y=0.5221511083334797
+a=wye,b=wye,x=0.20460330576630303,y=0.33831852551664776
+a=eks,b=wye,x=0.38139939387114097,y=0.13418874328430463
+a=wye,b=pan,x=0.5732889198020006,y=0.8636244699032729
+a=zee,b=pan,x=0.5271261600918548,y=0.49322128674835697
+a=eks,b=zee,x=0.6117840605678454,y=0.1878849191181694
+a=zee,b=wye,x=0.5985540091064224,y=0.976181385699006
+a=hat,b=wye,x=0.03144187646093577,y=0.7495507603507059
+a=pan,b=wye,x=0.5026260055412137,y=0.9526183602969864
+
+mlr --opprint --from ./reg_test/input/abixy put -q 
+  @output[NR] = $*;
+  end {
+    for ((nr, k), v in @output) {
+      if (nr == 4 || k == "i") {
+        unset @output[nr][k]
+      }
+    }
+    emitp @output, "NR", "k"
+  }
+
+NR k output
+1  a pan
+1  b pan
+1  x 0.3467901443380824
+1  y 0.7268028627434533
+2  a eks
+2  b pan
+2  x 0.7586799647899636
+2  y 0.5221511083334797
+3  a wye
+3  b wye
+3  x 0.20460330576630303
+3  y 0.33831852551664776
+5  a wye
+5  b pan
+5  x 0.5732889198020006
+5  y 0.8636244699032729
+6  a zee
+6  b pan
+6  x 0.5271261600918548
+6  y 0.49322128674835697
+7  a eks
+7  b zee
+7  x 0.6117840605678454
+7  y 0.1878849191181694
+8  a zee
+8  b wye
+8  x 0.5985540091064224
+8  y 0.976181385699006
+9  a hat
+9  b wye
+9  x 0.03144187646093577
+9  y 0.7495507603507059
+10 a pan
+10 b wye
+10 x 0.5026260055412137
+10 y 0.9526183602969864
+
 
 ================================================================
 DSL PATTERN-ACTION BLOCKS
diff --git a/c/reg_test/run b/c/reg_test/run
index 756cef366..ed5daafe4 100755
--- a/c/reg_test/run
+++ b/c/reg_test/run
@@ -1532,6 +1532,20 @@ run_mlr put 'unset $*; $aaa = 999' $indir/unset4.dkvp
 run_mlr put -q '@{variable.name} += $x; end{emit @{variable.name}}' $indir/abixy
 run_mlr put -q '@{variable.name}[$a] += $x; end{emit @{variable.name},"a"}' $indir/abixy
 
+run_mlr put 'for (k,v in $*) { if (k == "i") {unset $[k]}}' $indir/abixy
+
+run_mlr --opprint --from $indir/abixy put -q '
+  @output[NR] = $*;
+  end {
+    for ((nr, k), v in @output) {
+      if (nr == 4 || k == "i") {
+        unset @output[nr][k]
+      }
+    }
+    emitp @output, "NR", "k"
+  }
+'
+
 # ----------------------------------------------------------------
 announce DSL PATTERN-ACTION BLOCKS