diff --git a/include/g.hpp b/include/g.hpp
index 9f42c52..5e0f710 100644
--- a/include/g.hpp
+++ b/include/g.hpp
@@ -2,15 +2,11 @@
 #include <cmath>
 #include <vector>
 #include "span.h"
+#include "fp.hpp"
 
 namespace bls12_381
 {
 
-class fp;
-class fp2;
-class fp6;
-class fp12;
-
 // g1 is type for point in G1.
 // g1 is both used for Affine and Jacobian point representation.
 // If z is equal to one the point is considered as in affine form.
@@ -118,4 +114,4 @@ class g2
     static const std::array<uint64_t, 1> cofactorEFF;
 };
 
-} // namespace bls12_381
\ No newline at end of file
+} // namespace bls12_381