diff --git a/edge.cpp b/edge.cpp
index 6ed5c11..451b75d 100644
--- a/edge.cpp
+++ b/edge.cpp
@@ -204,7 +204,7 @@ bool edge::is_on_boundary()
 	if(boost::logic::indeterminate(boundary))
 		boundary = (f == NULL) || (g == NULL);
 
-	return(boundary == true);
+	return(bool(boundary) == true);
 }
 
 /*!
diff --git a/face.cpp b/face.cpp
index f361761..ab29993 100644
--- a/face.cpp
+++ b/face.cpp
@@ -209,7 +209,7 @@ bool face::is_obtuse()
 		obtuse = (a*a+b*b < c*c) || (b*b* + c*c < a*a) || (c*c + a*a < b*b);
 	}
 
-	return(obtuse == true);
+	return(bool(obtuse) == true);
 }
 
 } // end of namespace "psalm"