diff --git a/c_emulator/riscv_platform.c b/c_emulator/riscv_platform.c
index 5b9852800..2fdb63f92 100644
--- a/c_emulator/riscv_platform.c
+++ b/c_emulator/riscv_platform.c
@@ -108,7 +108,7 @@ mach_bits plat_rom_size(unit u)
 }
 
 // Provides entropy for the scalar cryptography extension.
-mach_bits plat_get_16_random_bits()
+mach_bits plat_get_16_random_bits(unit u)
 {
   return rv_16_random_bits();
 }
diff --git a/c_emulator/riscv_platform.h b/c_emulator/riscv_platform.h
index 3cc6f0270..341bd5964 100644
--- a/c_emulator/riscv_platform.h
+++ b/c_emulator/riscv_platform.h
@@ -26,7 +26,7 @@ mach_bits plat_rom_base(unit);
 mach_bits plat_rom_size(unit);
 
 // Provides entropy for the scalar cryptography extension.
-mach_bits plat_get_16_random_bits();
+mach_bits plat_get_16_random_bits(unit);
 
 mach_bits plat_clint_base(unit);
 mach_bits plat_clint_size(unit);