diff --git a/compile.c b/compile.c
index ef92a83846..d34376c572 100644
--- a/compile.c
+++ b/compile.c
@@ -2942,6 +2942,15 @@ iseq_peephole_optimize(rb_iseq_t *iseq, LINK_ELEMENT *list, const int do_tailcal
 	    else if (previ == BIN(newarray) && iseq_pop_newarray(iseq, (INSN*)prev)) {
 		ELEM_REMOVE(&iobj->link);
 	    }
+	    else if (previ == BIN(concatstrings)) {
+		if (OPERAND_AT(prev, 0) == INT2FIX(1)) {
+		    ELEM_REMOVE(prev);
+		}
+		else {
+		    ELEM_REMOVE(&iobj->link);
+		    INSN_OF(prev) = BIN(adjuststack);
+		}
+	    }
 	}
     }