diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index 3ab1ae6..ccbeb55 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -952,8 +952,8 @@
 			return -1;
 		}
 		if (rc != readlen) {
-			fprintf(stderr, "Read error on %s: "
-				"Attempted to read %d bytes but got %d\n",
+			fprintf(stderr,
+				"Read error on %s: Attempted to read %zd bytes but got %d\n",
 				DEVNAME(dev), readlen, rc);
 			return -1;
 		}