diff --git a/tools/gpio/gpio-watch.c b/tools/gpio/gpio-watch.c
index f229ec62301b..41e76d244192 100644
--- a/tools/gpio/gpio-watch.c
+++ b/tools/gpio/gpio-watch.c
@@ -10,6 +10,7 @@
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
 #include <linux/gpio.h>
 #include <poll.h>
 #include <stdbool.h>
@@ -86,8 +87,8 @@ int main(int argc, char **argv)
 				return EXIT_FAILURE;
 			}
 
-			printf("line %u: %s at %llu\n",
-			       chg.info.offset, event, chg.timestamp_ns);
+			printf("line %u: %s at %" PRIu64 "\n",
+			       chg.info.offset, event, (uint64_t)chg.timestamp_ns);
 		}
 	}