diff --git a/src/core/include/mp-units/framework/quantity.h b/src/core/include/mp-units/framework/quantity.h
index e87d0d97..d07fe215 100644
--- a/src/core/include/mp-units/framework/quantity.h
+++ b/src/core/include/mp-units/framework/quantity.h
@@ -640,7 +640,7 @@ public:
 
 // CTAD
 template<Representation Value, Reference R>
-explicit(false) quantity(Value v, R) -> quantity<R{}, Value>;
+quantity(Value v, R) -> quantity<R{}, Value>;
 
 template<Representation Value>
 explicit(false) quantity(Value) -> quantity<one, Value>;
diff --git a/src/core/include/mp-units/framework/quantity_point.h b/src/core/include/mp-units/framework/quantity_point.h
index fb0f1d5a..920abcab 100644
--- a/src/core/include/mp-units/framework/quantity_point.h
+++ b/src/core/include/mp-units/framework/quantity_point.h
@@ -546,7 +546,7 @@ public:
 
 // CTAD
 template<Quantity Q>
-quantity_point(Q q) -> quantity_point<Q::reference, default_point_origin(Q::reference), typename Q::rep>;
+explicit quantity_point(Q q) -> quantity_point<Q::reference, default_point_origin(Q::reference), typename Q::rep>;
 
 template<Quantity Q, PointOriginFor<Q::quantity_spec> PO>
 quantity_point(Q q, PO) -> quantity_point<Q::reference, PO{}, typename Q::rep>;