diff --git a/src/command.c b/src/command.c
index 2ff8398..4d205bb 100644
--- a/src/command.c
+++ b/src/command.c
@@ -219,7 +219,7 @@ static bool cmd_jtag_scan(target *t, int argc, const char **argv)
 		break;
 	}
 
-	if (devs <= 0) {
+	if (devs == 0) {
 		platform_nrst_set_val(false);
 		gdb_out("JTAG device scan failed!\n");
 		return false;
diff --git a/src/include/target.h b/src/include/target.h
index 7695fb9..4ec49d7 100644
--- a/src/include/target.h
+++ b/src/include/target.h
@@ -39,7 +39,7 @@ int platform_adiv5_swdp_scan(uint32_t targetid);
 int platform_jtag_scan(const uint8_t *lrlens);
 #endif
 int adiv5_swdp_scan(uint32_t targetid);
-int jtag_scan(const uint8_t *lrlens);
+uint32_t jtag_scan(const uint8_t *lrlens);
 
 int target_foreach(void (*cb)(int i, target *t, void *context), void *context);
 void target_list_free(void);
diff --git a/src/platforms/hosted/bmp_remote.c b/src/platforms/hosted/bmp_remote.c
index 11b8ae6..430bdda 100644
--- a/src/platforms/hosted/bmp_remote.c
+++ b/src/platforms/hosted/bmp_remote.c
@@ -384,7 +384,7 @@ void remote_adiv5_dp_defaults(ADIv5_DP_t *dp)
 	dp->mem_write_sized = remote_ap_mem_write_sized;
 }
 
-void remote_add_jtag_dev(int i, const jtag_dev_t *jtag_dev)
+void remote_add_jtag_dev(uint32_t i, const jtag_dev_t *jtag_dev)
 {
 	uint8_t construct[REMOTE_MAX_MSG_SIZE];
 	int s = snprintf((char *)construct, REMOTE_MAX_MSG_SIZE,
diff --git a/src/platforms/hosted/bmp_remote.h b/src/platforms/hosted/bmp_remote.h
index bcf4cbc..7c09bbc 100644
--- a/src/platforms/hosted/bmp_remote.h
+++ b/src/platforms/hosted/bmp_remote.h
@@ -40,6 +40,6 @@ void remote_max_frequency_set(uint32_t freq);
 uint32_t remote_max_frequency_get(void);
 const char *platform_target_voltage(void);
 void remote_adiv5_dp_defaults(ADIv5_DP_t *dp);
-void remote_add_jtag_dev(int i, const jtag_dev_t *jtag_dev);
+void remote_add_jtag_dev(uint32_t i, const jtag_dev_t *jtag_dev);
 #define __BMP_REMOTE_H_
 #endif
diff --git a/src/platforms/hosted/dap.c b/src/platforms/hosted/dap.c
index 196b63b..6edf8a0 100644
--- a/src/platforms/hosted/dap.c
+++ b/src/platforms/hosted/dap.c
@@ -748,7 +748,7 @@ void dap_jtagtap_tdi_tdo_seq(
 int dap_jtag_configure(void)
 {
 	uint8_t buf[64], *p = &buf[2];
-	int i = 0;
+	uint32_t i = 0;
 	for (; i < jtag_dev_count; i++) {
 		struct jtag_dev_s *jtag_dev = &jtag_devs[i];
 		*p++ = jtag_dev->ir_len;
diff --git a/src/platforms/hosted/platform.c b/src/platforms/hosted/platform.c
index b77c617..18538e0 100644
--- a/src/platforms/hosted/platform.c
+++ b/src/platforms/hosted/platform.c
@@ -172,7 +172,7 @@ int swdptap_init(ADIv5_DP_t *dp)
 	return -1;
 }
 
-void platform_add_jtag_dev(int i, const jtag_dev_t *jtag_dev)
+void platform_add_jtag_dev(uint32_t i, const jtag_dev_t *jtag_dev)
 {
 	if (info.bmp_type == BMP_TYPE_BMP)
 		remote_add_jtag_dev(i, jtag_dev);
diff --git a/src/platforms/hosted/stlinkv2.c b/src/platforms/hosted/stlinkv2.c
index ca2f843..e5b8202 100644
--- a/src/platforms/hosted/stlinkv2.c
+++ b/src/platforms/hosted/stlinkv2.c
@@ -1029,10 +1029,10 @@ int jtag_scan_stlinkv2(bmp_info_t *info, const uint8_t *irlens)
 		return 0;
 	jtag_dev_count = stlink_read_idcodes(info, idcodes);
 	/* Check for known devices and handle accordingly */
-	for(int i = 0; i < jtag_dev_count; i++)
+	for(uint32_t i = 0; i < jtag_dev_count; i++)
 		jtag_devs[i].jd_idcode = idcodes[i];
-	for(int i = 0; i < jtag_dev_count; i++)
-		for(int j = 0; dev_descr[j].idcode; j++)
+	for(uint32_t i = 0; i < jtag_dev_count; i++)
+		for(size_t j = 0; dev_descr[j].idcode; j++)
 			if((jtag_devs[i].jd_idcode & dev_descr[j].idmask) ==
 			   dev_descr[j].idcode) {
 				if(dev_descr[j].handler)
diff --git a/src/remote.c b/src/remote.c
index 3a80cbe..a38015e 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -254,7 +254,7 @@ static void remotePacketProcessJTAG(unsigned i, char *packet)
 			remote_respond(REMOTE_RESP_ERR,REMOTE_ERROR_WRONGLEN);
 		} else {
 			memset(&jtag_dev, 0, sizeof(jtag_dev));
-			uint8_t index        = remotehston(2, &packet[ 2]);
+			const uint32_t index = remotehston(2, &packet[ 2]);
 			jtag_dev.dr_prescan  = remotehston(2, &packet[ 4]);
 			jtag_dev.dr_postscan = remotehston(2, &packet[ 6]);
 			jtag_dev.ir_len      = remotehston(2, &packet[ 8]);
diff --git a/src/target/adiv5.h b/src/target/adiv5.h
index 7e162db..6d6a3af 100644
--- a/src/target/adiv5.h
+++ b/src/target/adiv5.h
@@ -318,7 +318,7 @@ ADIv5_AP_t *adiv5_new_ap(ADIv5_DP_t *dp, uint8_t apsel);
 void remote_jtag_dev(const jtag_dev_t *jtag_dev);
 void adiv5_ap_ref(ADIv5_AP_t *ap);
 void adiv5_ap_unref(ADIv5_AP_t *ap);
-void platform_add_jtag_dev(const int dev_index, const jtag_dev_t *jtag_dev);
+void platform_add_jtag_dev(uint32_t dev_index, const jtag_dev_t *jtag_dev);
 
 void adiv5_jtag_dp_handler(uint8_t jd_index);
 int platform_jtag_dp_init(ADIv5_DP_t *dp);
diff --git a/src/target/jtag_scan.c b/src/target/jtag_scan.c
index 0c51ec2..3412f7d 100644
--- a/src/target/jtag_scan.c
+++ b/src/target/jtag_scan.c
@@ -38,7 +38,7 @@ uint32_t jtag_dev_count = 0;
 static const uint8_t ones[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
 
 #if PC_HOSTED == 0
-void jtag_add_device(const int dev_index, const jtag_dev_t *jtag_dev)
+void jtag_add_device(const uint32_t dev_index, const jtag_dev_t *jtag_dev)
 {
 	if (dev_index == 0)
 		memset(&jtag_devs, 0, sizeof(jtag_devs));
@@ -64,7 +64,7 @@ void jtag_add_device(const int dev_index, const jtag_dev_t *jtag_dev)
  *	continue to next device. If this is one shift out the remaining 31 bits
  *	of the IDCODE register.
  */
-int jtag_scan(const uint8_t *irlens)
+uint32_t jtag_scan(const uint8_t *irlens)
 {
 	target_list_free();
 
@@ -140,14 +140,14 @@ int jtag_scan(const uint8_t *irlens)
 
 		if (jtag_dev_count > JTAG_MAX_DEVS) {
 			DEBUG_WARN("jtag_scan: Maximum device count exceeded\n");
-			jtag_dev_count = -1;
-			return -1;
+			jtag_dev_count = 0;
+			return 0;
 		}
 
 		if (jtag_devs[jtag_dev_count].ir_len > JTAG_MAX_IR_LEN) {
 			DEBUG_WARN("jtag_scan: Maximum IR length exceeded\n");
-			jtag_dev_count = -1;
-			return -1;
+			jtag_dev_count = 0;
+			return 0;
 		}
 	}
 
@@ -166,8 +166,8 @@ int jtag_scan(const uint8_t *irlens)
 
 	if (device != jtag_dev_count) {
 		DEBUG_WARN("jtag_scan: Sanity check failed: BYPASS dev count doesn't match IR scan\n");
-		jtag_dev_count = -1;
-		return -1;
+		jtag_dev_count = 0;
+		return 0;
 	}
 
 	DEBUG_INFO("Return to Run-Test/Idle\n");
diff --git a/src/target/jtag_scan.h b/src/target/jtag_scan.h
index 8a38bea..d820036 100644
--- a/src/target/jtag_scan.h
+++ b/src/target/jtag_scan.h
@@ -46,5 +46,6 @@ extern uint32_t jtag_dev_count;
 
 void jtag_dev_write_ir(jtag_proc_t *jp, uint8_t jd_index, uint32_t ir);
 void jtag_dev_shift_dr(jtag_proc_t *jp, uint8_t jd_index, uint8_t *dout, const uint8_t *din, int ticks);
-void jtag_add_device(const int dev_index, const jtag_dev_t *jtag_dev);
-#endif
+void jtag_add_device(uint32_t dev_index, const jtag_dev_t *jtag_dev);
+
+#endif /*__JTAG_SCAN_H*/