diff --git a/repos/base-hw/src/bootstrap/spec/riscv/board.h b/repos/base-hw/src/bootstrap/spec/riscv/board.h
index a6eabdfc8..29d6105be 100644
--- a/repos/base-hw/src/bootstrap/spec/riscv/board.h
+++ b/repos/base-hw/src/bootstrap/spec/riscv/board.h
@@ -29,7 +29,7 @@ namespace Board {
 
 	enum { UART_BASE, UART_CLOCK };
 	struct Serial : Hw::Riscv_uart {
-		Serial(unsigned, unsigned, unsigned) {} };
+		Serial(Genode::addr_t, Genode::size_t, unsigned) {} };
 }
 
 template <typename E, unsigned B, unsigned S>
diff --git a/repos/base-hw/src/core/spec/riscv/board.h b/repos/base-hw/src/core/spec/riscv/board.h
index 908413fa3..01c956e87 100644
--- a/repos/base-hw/src/core/spec/riscv/board.h
+++ b/repos/base-hw/src/core/spec/riscv/board.h
@@ -19,7 +19,7 @@
 namespace Board {
 	enum { UART_BASE, UART_CLOCK };
 	struct Serial : Hw::Riscv_uart {
-		Serial(unsigned, unsigned, unsigned) {} };
+		Serial(Genode::addr_t, Genode::size_t, unsigned) {} };
 }
 
 #endif /* _CORE__SPEC__RISCV__BOARD_H_ */