diff --git a/third_party/ibis/ibis_oracle/client.py b/third_party/ibis/ibis_oracle/client.py
index 1bb5d219e..85e9b6a4a 100644
--- a/third_party/ibis/ibis_oracle/client.py
+++ b/third_party/ibis/ibis_oracle/client.py
@@ -43,6 +43,8 @@ def sa_oracle_LONG(_, satype, nullable=True):
 
 @dt.dtype.register(OracleDialect_cx_oracle, sa.dialects.oracle.NUMBER)
 def sa_oracle_NUMBER(_, satype, nullable=True):
+    if not satype.precision and not satype.scale:
+        return dt.Decimal(38, 0, nullable=nullable)
     return dt.Decimal(satype.precision, satype.scale, nullable=nullable)