diff --git a/serprog.c b/serprog.c
index c68449a79..57196a986 100644
--- a/serprog.c
+++ b/serprog.c
@@ -15,6 +15,7 @@
  * GNU General Public License for more details.
  */
 
+#include <stdbool.h>
 #include <stdio.h>
 #if ! IS_WINDOWS /* stuff (presumably) needed for sockets only */
 #include <stdlib.h>
@@ -571,7 +572,7 @@ static int serprog_init(const struct programmer_cfg *cfg)
 	unsigned char rbuf[3];
 	unsigned char c;
 	char *device;
-	int have_device = 0;
+	bool have_device = false;
 
 	/* the parameter is either of format "dev=/dev/device[:baud]" or "ip=ip:port" */
 	device = extract_programmer_param_str(cfg, "dev");
@@ -598,7 +599,7 @@ static int serprog_init(const struct programmer_cfg *cfg)
 				free(device);
 				return 1;
 			}
-			have_device++;
+			have_device = true;
 		}
 	}
 
@@ -637,7 +638,7 @@ static int serprog_init(const struct programmer_cfg *cfg)
 				free(device);
 				return 1;
 			}
-			have_device++;
+			have_device = true;
 		}
 	}
 	if (device && !strlen(device)) {