diff --git a/src/kits/interface/AffineTransform.cpp b/src/kits/interface/AffineTransform.cpp
index 149435dda1..2bc72c9e38 100644
--- a/src/kits/interface/AffineTransform.cpp
+++ b/src/kits/interface/AffineTransform.cpp
@@ -98,7 +98,7 @@ BAffineTransform::FlattenedSize() const
 status_t
 BAffineTransform::Flatten(void* _buffer, ssize_t size) const
 {
-	if (_buffer == NULL || size < FlattenedSize())
+	if (_buffer == NULL || size < BAffineTransform::FlattenedSize())
 		return B_BAD_VALUE;
 
 	double* buffer = reinterpret_cast<double*>(_buffer);
@@ -117,8 +117,10 @@ BAffineTransform::Flatten(void* _buffer, ssize_t size) const
 status_t
 BAffineTransform::Unflatten(type_code code, const void* _buffer, ssize_t size)
 {
-	if (_buffer == NULL || size < FlattenedSize() || code != TypeCode())
+	if (_buffer == NULL || size < BAffineTransform::FlattenedSize()
+			|| code != BAffineTransform::TypeCode()) {
 		return B_BAD_VALUE;
+	}
 
 	const double* buffer = reinterpret_cast<const double*>(_buffer);