diff --git a/test/svd_fill.h b/test/svd_fill.h
index 5c2c61f8e..3877c0c7e 100644
--- a/test/svd_fill.h
+++ b/test/svd_fill.h
@@ -8,12 +8,14 @@
 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 template<typename T>
-Array<T,4,1> four_denorms() { return four_denorms<double>().cast<T>(); }
+Array<T,4,1> four_denorms();
 
 template<>
 Array4f four_denorms() { return Array4f(5.60844e-39f, -5.60844e-39f, 4.94e-44f, -4.94e-44f); }
 template<>
 Array4d four_denorms() { return Array4d(5.60844e-313, -5.60844e-313, 4.94e-324, -4.94e-324); }
+template<typename T>
+Array<T,4,1> four_denorms() { return four_denorms<double>().cast<T>(); }
 
 template<typename MatrixType>
 void svd_fill_random(MatrixType &m, int Option = 0)