diff --git a/core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java b/core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java
index f907f4ba1421..74e85c76f70e 100644
--- a/core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java
+++ b/core/src/main/java/org/apache/calcite/sql/validate/SqlValidatorUtil.java
@@ -1560,7 +1560,12 @@ private static void adjustTypeForMultisetConstructor(
         if (adjustedOperands == null) {
           adjustedOperands = new ArrayList<>(operands);
         }
-        adjustedOperands.set(i, castTo(operands.get(i), elementType));
+        SqlCall cast = (SqlCall) castTo(operands.get(i), elementType);
+        // This CAST was generated with the built-in operator; validate its
+        // operands directly instead of resolving the function again by name.
+        cast.getOperator().validateOperands(
+            sqlCallBinding.getValidator(), sqlCallBinding.getScope(), cast);
+        adjustedOperands.set(i, cast);
       }
     }
     if (adjustedOperands != null) {
diff --git a/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java b/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
index 3915e5723cb8..77d6b1d7d5b0 100644
--- a/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
+++ b/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
@@ -41,6 +41,7 @@
 import org.apache.calcite.sql.SqlOperatorTable;
 import org.apache.calcite.sql.SqlSelect;
 import org.apache.calcite.sql.SqlSpecialOperator;
+import org.apache.calcite.sql.SqlSyntax;
 import org.apache.calcite.sql.fun.SqlCase;
 import org.apache.calcite.sql.fun.SqlLibrary;
 import org.apache.calcite.sql.fun.SqlLibraryOperatorTableFactory;
@@ -62,6 +63,7 @@
 import org.apache.calcite.sql.validate.SqlConformanceEnum;
 import org.apache.calcite.sql.validate.SqlDelegatingConformance;
 import org.apache.calcite.sql.validate.SqlMonotonicity;
+import org.apache.calcite.sql.validate.SqlNameMatcher;
 import org.apache.calcite.sql.validate.SqlValidator;
 import org.apache.calcite.sql.validate.SqlValidatorCatalogReader;
 import org.apache.calcite.sql.validate.SqlValidatorImpl;
@@ -9756,6 +9758,41 @@ void testGroupExpressionEquivalenceParams() {
         .columnType("CHAR(3) ARRAY NOT NULL");
   }
 
+  @Test void testValidateOperandsCachesGeneratedCastType()
+      throws SqlParseException {
+    final int[] castLookups = {0};
+    final SqlValidator validator = fixture()
+        .withFactory(
+            factory -> factory.withOperatorTable(operatorTable ->
+            new SqlOperatorTable() {
+              @Override public void lookupOperatorOverloads(SqlIdentifier opName,
+                  SqlFunctionCategory category, SqlSyntax syntax,
+                  List<SqlOperator> operatorList, SqlNameMatcher nameMatcher) {
+                if (opName.isSimple() && opName.getSimple().equals("CAST")) {
+                  castLookups[0]++;
+                }
+                operatorTable.lookupOperatorOverloads(
+                    opName, category, syntax, operatorList, nameMatcher);
+              }
+
+              @Override public List<SqlOperator> getOperatorList() {
+                return operatorTable.getOperatorList();
+              }
+            }))
+        .factory.createValidator();
+    final SqlCall cast = (SqlCall) SqlParser
+        .create("cast('a' as varchar(2))", SqlParser.config())
+        .parseExpression();
+    final SqlValidatorScope scope = validator.getEmptyScope();
+    validator.deriveType(scope, cast.getOperandList().get(0));
+    // SqlValidatorUtil relies on validateOperands caching the generated CAST
+    // type so a later deriveType call does not resolve the operator by name.
+    cast.getOperator().validateOperands(validator, scope, cast);
+
+    validator.deriveType(scope, cast);
+    assertThat(castLookups[0], is(0));
+  }
+
   /**
    * Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-4999">[CALCITE-4999]