diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index 0388122ab3..8e5e25f86a 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -285,6 +285,7 @@ int mbedtls_ecp_mod_p448_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_CURVE448_ENABLED */
 
+#if defined(MBEDTLS_ECP_WITH_MPI_UINT)
 /** Initialise a modulus with hard-coded const curve data.
  *
  * \note            The caller is responsible for the \p N modulus' memory.
@@ -306,6 +307,7 @@ MBEDTLS_STATIC_TESTABLE
 int mbedtls_ecp_modulus_setup(mbedtls_mpi_mod_modulus *N,
                               const mbedtls_ecp_group_id id,
                               const mbedtls_ecp_modulus_type ctype);
+#endif /* MBEDTLS_ECP_WITH_MPI_UINT */
 
 #endif /* MBEDTLS_TEST_HOOKS && MBEDTLS_ECP_C */