diff --git a/intel/intel_decode.c b/intel/intel_decode.c
index 1e632954..1b5f858e 100644
--- a/intel/intel_decode.c
+++ b/intel/intel_decode.c
@@ -87,6 +87,10 @@ static float int_as_float(uint32_t intval)
 	return uval.f;
 }
 
+static void
+instr_out(uint32_t *data, uint32_t hw_offset, unsigned int index,
+	  const char *fmt, ...) __attribute__((format(__printf__, 4, 5)));
+
 static void
 instr_out(uint32_t *data, uint32_t hw_offset, unsigned int index,
 	  const char *fmt, ...)