diff --git a/pkg/ccl/logictestccl/testdata/logic_test/udf_plpgsql b/pkg/ccl/logictestccl/testdata/logic_test/udf_plpgsql
index 91a97576e0f4..35ca8aaf891a 100644
--- a/pkg/ccl/logictestccl/testdata/logic_test/udf_plpgsql
+++ b/pkg/ccl/logictestccl/testdata/logic_test/udf_plpgsql
@@ -3409,3 +3409,42 @@ NOTICE: i: 4 j: 2
 NOTICE: outer_counter: 4 inner_counter: 8
 
 subtest end
+
+# Regression test for a failure to step the read sequence number after catching
+# an exception and restoring a savepoint (#156412).
+subtest regression_156412
+
+statement ok
+CREATE TABLE t122278 (pk INT PRIMARY KEY);
+
+statement ok
+CREATE FUNCTION f(n INT) RETURNS INT AS $$
+  BEGIN
+    BEGIN
+      IF n = 0 THEN
+        RETURN 1 // 0;
+      END IF;
+    EXCEPTION
+      WHEN division_by_zero THEN
+        RETURN (SELECT 100 + count(*) FROM t122278);
+    END;
+    RETURN 1 // 0;
+  EXCEPTION
+    WHEN division_by_zero THEN
+      RETURN (SELECT 200 + count(*) FROM t122278);
+  END
+$$ LANGUAGE PLpgSQL;
+
+statement ok
+BEGIN;
+
+statement ok
+INSERT INTO t122278 values (1);
+
+statement ok
+SELECT f(0);
+
+statement ok
+COMMIT;
+
+subtest end
diff --git a/pkg/kv/txn.go b/pkg/kv/txn.go
index c1f6bd824293..8099f93b2c8e 100644
--- a/pkg/kv/txn.go
+++ b/pkg/kv/txn.go
@@ -1825,6 +1825,9 @@ func (txn *Txn) CreateSavepoint(ctx context.Context) (SavepointToken, error) {
 // and can be reused later (e.g. to release or roll back again).
 //
 // This method is only valid when called on RootTxns.
+//
+// NB: after calling RollbackToSavepoint, the transaction's read sequence number
+// must be stepped by calling Step() before any further reads are performed.
 func (txn *Txn) RollbackToSavepoint(ctx context.Context, s SavepointToken) error {
 	txn.mu.Lock()
 	defer txn.mu.Unlock()
diff --git a/pkg/sql/routine.go b/pkg/sql/routine.go
index 97b2966c109b..effca937da8f 100644
--- a/pkg/sql/routine.go
+++ b/pkg/sql/routine.go
@@ -460,12 +460,19 @@ func (g *routineGenerator) handleException(ctx context.Context, err error) error
 			g.reset(ctx, g.p, branch, args)
 
 			// Configure stepping for volatile routines so that mutations made by the
-			// invoking statement are visible to the routine.
+			// invoking statement are visible to the routine. Make sure to also step
+			// before caching the read sequence number, since the read sequence number
+			// may be part of "ignored" list set when restoring the savepoint above.
 			var prevSteppingMode kv.SteppingMode
 			var prevSeqNum enginepb.TxnSeq
 			txn := g.p.Txn()
 			if g.expr.EnableStepping {
 				prevSteppingMode = txn.ConfigureStepping(ctx, kv.SteppingEnabled)
+				stepErr := txn.Step(ctx, false /* allowReadTimestampStep */)
+				if stepErr != nil {
+					// This error is unexpected, so return immediately.
+					return errors.CombineErrors(err, errors.WithAssertionFailure(stepErr))
+				}
 				prevSeqNum = txn.GetReadSeqNum()
 			}