diff --git a/include/qpdf/PDFVersion.hh b/include/qpdf/PDFVersion.hh
index 2ce231f5..874e8f55 100644
--- a/include/qpdf/PDFVersion.hh
+++ b/include/qpdf/PDFVersion.hh
@@ -41,6 +41,8 @@ class PDFVersion
     QPDF_DLL
     PDFVersion(PDFVersion const&) = default;
     QPDF_DLL
+    PDFVersion& operator=(PDFVersion const&) = default;
+    QPDF_DLL
     PDFVersion(int major, int minor, int extension = 0);
     QPDF_DLL
     bool operator<(PDFVersion const& rhs) const;