diff --git a/pkg/internal/sqlsmith/relational.go b/pkg/internal/sqlsmith/relational.go
index a13aaa3d3740..300d8bd91d41 100644
--- a/pkg/internal/sqlsmith/relational.go
+++ b/pkg/internal/sqlsmith/relational.go
@@ -14,6 +14,7 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/sql/randgen"
 	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
 	"github.com/cockroachdb/cockroach/pkg/sql/types"
+	"github.com/lib/pq/oid"
 )
 
 func (s *Smither) makeStmt() (stmt tree.Statement, ok bool) {
@@ -235,6 +236,10 @@ func makeEquiJoinExpr(s *Smither, refs colRefs, forJoin bool) (tree.TableExpr, c
 	for (cond == nil || s.coin()) && len(available) > 0 {
 		v := available[0]
 		available = available[1:]
+		// You can't compare voids.
+		if v[0].ResolvedType().Oid() == oid.T_void || v[1].ResolvedType().Oid() == oid.T_void {
+			continue
+		}
 		expr := tree.NewTypedComparisonExpr(tree.MakeComparisonOperator(tree.EQ), v[0], v[1])
 		if cond == nil {
 			cond = expr
diff --git a/pkg/internal/sqlsmith/scalar.go b/pkg/internal/sqlsmith/scalar.go
index 5dffa3108ef9..1f59d8db37bc 100644
--- a/pkg/internal/sqlsmith/scalar.go
+++ b/pkg/internal/sqlsmith/scalar.go
@@ -277,7 +277,7 @@ var compareOps = [...]tree.ComparisonOperatorSymbol{
 }
 
 func makeCompareOp(s *Smither, typ *types.T, refs colRefs) (tree.TypedExpr, bool) {
-	if f := typ.Family(); f != types.BoolFamily && f != types.AnyFamily {
+	if f := typ.Family(); f != types.BoolFamily && f != types.AnyFamily && f != types.VoidFamily {
 		return nil, false
 	}
 	typ = s.randScalarType()