diff --git a/firmware/payloads/test_main.c b/firmware/payloads/test_main.c
index 666ce7c0..957f963f 100644
--- a/firmware/payloads/test_main.c
+++ b/firmware/payloads/test_main.c
@@ -14,17 +14,9 @@ do {							\
 	__asm__ __volatile__ ("wfi" ::: "memory");	\
 } while (0)
 
-static void sbi_puts(const char *str)
-{
-	while (*str) {
-		SBI_ECALL_1(SBI_ECALL_CONSOLE_PUTCHAR, *str);
-		str++;
-	}
-}
-
 void test_main(unsigned long a0, unsigned long a1)
 {
-	sbi_puts("\nTest payload running\n");
+	sbi_ecall_console_puts("\nTest payload running\n");
 
 	while (1)
 		wfi();
diff --git a/include/sbi/sbi_ecall_interface.h b/include/sbi/sbi_ecall_interface.h
index 53de6a4d..1ea26764 100644
--- a/include/sbi/sbi_ecall_interface.h
+++ b/include/sbi/sbi_ecall_interface.h
@@ -24,7 +24,7 @@
 	register unsigned long a0 asm ("a0") = (unsigned long)(__a0);	\
 	register unsigned long a1 asm ("a1") = (unsigned long)(__a1);	\
 	register unsigned long a2 asm ("a2") = (unsigned long)(__a2);	\
-	register unsigned long a7 asm ("a7") = (unsigned long)(__num);\
+	register unsigned long a7 asm ("a7") = (unsigned long)(__num);	\
 	asm volatile ("ecall"						\
 		      : "+r" (a0)					\
 		      : "r" (a1), "r" (a2), "r" (a7)			\
@@ -36,4 +36,13 @@
 #define SBI_ECALL_1(__num, __a0)		SBI_ECALL(__num, __a0, 0, 0)
 #define SBI_ECALL_2(__num, __a0, __a1)		SBI_ECALL(__num, __a0, __a1, 0)
 
+#define sbi_ecall_console_putc(c)		\
+	SBI_ECALL_1(SBI_ECALL_CONSOLE_PUTCHAR, (c));
+
+static inline void sbi_ecall_console_puts(const char *str)
+{
+	while (str && *str)
+		sbi_ecall_console_putc(*str++);
+}
+
 #endif