6 files changed, 36 insertions, 2 deletions
diff --git a/src/cmd/compile/internal/types2/issues_test.go b/src/cmd/compile/internal/types2/issues_test.go
index a8893cf6de..0117571f7b 100644
--- a/src/cmd/compile/internal/types2/issues_test.go
+++ b/src/cmd/compile/internal/types2/issues_test.go
@@ -1076,3 +1076,20 @@ func TestIssue59831(t *testing.T) {
 		}
 	}
 }
+
+func TestIssue64759(t *testing.T) {
+	const src = `
+//go:build go1.18
+package p
+
+func f[S ~[]E, E any](S) {}
+
+func _() {
+	f([]string{})
+}
+`
+	// Per the go:build directive, the source must typecheck
+	// even though the (module) Go version is set to go1.17.
+	conf := Config{GoVersion: "go1.17"}
+	mustTypecheck(src, &conf, nil)
+}
diff --git a/src/cmd/compile/internal/types2/subst.go b/src/cmd/compile/internal/types2/subst.go
index aefa53603f..09dc58527a 100644
--- a/src/cmd/compile/internal/types2/subst.go
+++ b/src/cmd/compile/internal/types2/subst.go
@@ -169,6 +169,7 @@ func (subst *subster) typ(typ Type) Type {
 		if mcopied || ecopied {
 			iface := subst.check.newInterface()
 			iface.embeddeds = embeddeds
+			iface.embedPos = t.embedPos
 			iface.implicit = t.implicit
 			assert(t.complete) // otherwise we are copying incomplete data
 			iface.complete = t.complete
diff --git a/src/cmd/compile/internal/types2/typeset.go b/src/cmd/compile/internal/types2/typeset.go
index 719041657c..a6ccfdb80c 100644
--- a/src/cmd/compile/internal/types2/typeset.go
+++ b/src/cmd/compile/internal/types2/typeset.go
@@ -304,7 +304,6 @@ func computeInterfaceTypeSet(check *Checker, pos syntax.Pos, ityp *Interface) *_
 		// separately. Here we only need to intersect the term lists and comparable bits.
 		allTerms, allComparable = intersectTermLists(allTerms, allComparable, terms, comparable)
 	}
-	ityp.embedPos = nil // not needed anymore (errors have been reported)
 
 	ityp.tset.comparable = allComparable
 	if len(allMethods) != 0 {
diff --git a/src/go/types/issues_test.go b/src/go/types/issues_test.go
index b4c8218bc4..6f9d5978e7 100644
--- a/src/go/types/issues_test.go
+++ b/src/go/types/issues_test.go
@@ -1086,3 +1086,20 @@ func TestIssue59831(t *testing.T) {
 		}
 	}
 }
+
+func TestIssue64759(t *testing.T) {
+	const src = `
+//go:build go1.18
+package p
+
+func f[S ~[]E, E any](S) {}
+
+func _() {
+	f([]string{})
+}
+`
+	// Per the go:build directive, the source must typecheck
+	// even though the (module) Go version is set to go1.17.
+	conf := Config{GoVersion: "go1.17"}
+	mustTypecheck(src, &conf, nil)
+}
diff --git a/src/go/types/subst.go b/src/go/types/subst.go
index 13d3dcbf1e..1934ebab2b 100644
--- a/src/go/types/subst.go
+++ b/src/go/types/subst.go
@@ -171,6 +171,7 @@ func (subst *subster) typ(typ Type) Type {
 		if mcopied || ecopied {
 			iface := subst.check.newInterface()
 			iface.embeddeds = embeddeds
+			iface.embedPos = t.embedPos
 			iface.implicit = t.implicit
 			assert(t.complete) // otherwise we are copying incomplete data
 			iface.complete = t.complete
diff --git a/src/go/types/typeset.go b/src/go/types/typeset.go
index 8d8c490c6a..d164749996 100644
--- a/src/go/types/typeset.go
+++ b/src/go/types/typeset.go
@@ -302,7 +302,6 @@ func computeInterfaceTypeSet(check *Checker, pos token.Pos, ityp *Interface) *_T
 		// separately. Here we only need to intersect the term lists and comparable bits.
 		allTerms, allComparable = intersectTermLists(allTerms, allComparable, terms, comparable)
 	}
-	ityp.embedPos = nil // not needed anymore (errors have been reported)
 
 	ityp.tset.comparable = allComparable
 	if len(allMethods) != 0 {