1 files changed, 12 insertions, 1 deletions
diff --git a/prog/encoding.go b/prog/encoding.go
index b5d5114ca..e925e7918 100644
--- a/prog/encoding.go
+++ b/prog/encoding.go
@@ -257,9 +257,13 @@ func (target *Target) Deserialize(data []byte, mode DeserializeMode) (*Prog, err
 	// This validation is done even in non-debug mode because deserialization
 	// procedure does not catch all bugs (e.g. mismatched types).
 	// And we can receive bad programs from corpus and hub.
-	if err := prog.validate(); err != nil {
+	if err := prog.validateWithOpts(validationOptions{
+		// Don't validate auto-set conditional fields. We'll patch them later.
+		ignoreTransient: true,
+	}); err != nil {
 		return nil, err
 	}
+	p.fixupConditionals(prog)
 	if p.autos != nil {
 		p.fixupAutos(prog)
 	}
@@ -1154,6 +1158,13 @@ func (p *parser) fixupAutos(prog *Prog) {
 	}
 }
 
+func (p *parser) fixupConditionals(prog *Prog) {
+	for _, c := range prog.Calls {
+		// Only overwrite transient union fields.
+		c.setDefaultConditions(p.target, true)
+	}
+}
+
 func (p *parser) Scan() bool {
 	if p.e != nil || len(p.data) == 0 {
 		return false