diff --git a/meson.build b/meson.build
index 363a594645c..531e3fe16c9 100644
--- a/meson.build
+++ b/meson.build
@@ -94,7 +94,7 @@ extended_warnings = [
 	'-Wbad-function-cast',
 	# '-Wcast-align=strict',
 	'-Wcast-function-type',
-	# '-Wcast-qual',
+	'-Wcast-qual',
 	# '-Wconversion',
 	'-Wdangling-else',
 	'-Wdouble-promotion',
diff --git a/src/gdb_main.c b/src/gdb_main.c
index 4bde81c17b8..9cca19e0119 100644
--- a/src/gdb_main.c
+++ b/src/gdb_main.c
@@ -1,8 +1,10 @@
 /*
  * This file is part of the Black Magic Debug project.
  *
- * Copyright (C) 2011  Black Sphere Technologies Ltd.
+ * Copyright (C) 2011 Black Sphere Technologies Ltd.
  * Written by Gareth McMullin <gareth@blacksphere.co.nz>
+ * Copyright (C) 2022-2024 1BitSquared <info@1bitsquared.com>
+ * Modified by Rachel Mant <git@dragonmux.network>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -488,7 +490,10 @@ static void exec_q_feature_read(const char *packet, const size_t length)
 	}
 	const char *const description = target_regs_description(target);
 	handle_q_string_reply(description ? description : "", packet);
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	free((void *)description);
+#pragma GCC diagnostic pop
 }
 
 static void exec_q_crc(const char *packet, const size_t length)
@@ -789,7 +794,7 @@ static void exec_v_flash_write(const char *packet, const size_t length)
 		/* Write Flash Memory */
 		const uint32_t count = length - (size_t)(rest - packet);
 		DEBUG_GDB("Flash Write %08" PRIX32 " %08" PRIX32 "\n", addr, count);
-		if (cur_target && target_flash_write(cur_target, addr, (uint8_t *)rest, count))
+		if (cur_target && target_flash_write(cur_target, addr, (const uint8_t *)rest, count))
 			gdb_putpacketz("OK");
 		else {
 			target_flash_complete(cur_target);
diff --git a/src/platforms/hosted/gdb_if.c b/src/platforms/hosted/gdb_if.c
index 09bf16a4b1b..26d65ac8f80 100644
--- a/src/platforms/hosted/gdb_if.c
+++ b/src/platforms/hosted/gdb_if.c
@@ -258,7 +258,7 @@ int gdb_if_init(void)
 				DEBUG_WARN("Listening on IPv6 only.\n");
 		}
 
-		if (bind(gdb_if_serv, (sockaddr_s *)&addr, family_to_size(addr.ss_family)) == -1) {
+		if (bind(gdb_if_serv, (const sockaddr_s *)&addr, family_to_size(addr.ss_family)) == -1) {
 			handle_error(gdb_if_serv, "binding socket");
 			continue;
 		}
diff --git a/src/platforms/hosted/probe_info.c b/src/platforms/hosted/probe_info.c
index 678f59084fe..b068b8dfbd6 100644
--- a/src/platforms/hosted/probe_info.c
+++ b/src/platforms/hosted/probe_info.c
@@ -80,23 +80,26 @@ size_t probe_info_count(const probe_info_s *const list)
 	return probes;
 }
 
-void probe_info_free(probe_info_s *const probe_info)
+void probe_info_free(const probe_info_s *const probe_info)
 {
 #if HOSTED_BMP_ONLY == 0
 	if (probe_info->device)
 		libusb_unref_device(probe_info->device);
 #endif
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	free((void *)probe_info->manufacturer);
 	free((void *)probe_info->product);
 	free((void *)probe_info->serial);
 	free((void *)probe_info->version);
-	free(probe_info);
+	free((void *)probe_info);
+#pragma GCC diagnostic pop
 }
 
 void probe_info_list_free(const probe_info_s *list)
 {
 	while (list) {
-		probe_info_s *probe_info = (probe_info_s *)list;
+		const probe_info_s *const probe_info = (const probe_info_s *)list;
 		list = probe_info->next;
 		probe_info_free(probe_info);
 	}
diff --git a/src/remote.c b/src/remote.c
index ed04bcc8859..278fb43fead 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -270,12 +270,12 @@ static void remote_packet_process_general(char *packet, const size_t packet_len)
 		remote_respond(REMOTE_RESP_OK, platform_nrst_get_val());
 		break;
 	case REMOTE_FREQ_SET:
-		platform_max_frequency_set(hex_string_to_num(8, packet + 2));
+		platform_max_frequency_set(hex_string_to_num(8U, packet + 2U));
 		remote_respond(REMOTE_RESP_OK, 0);
 		break;
 	case REMOTE_FREQ_GET: {
 		const uint32_t freq = platform_max_frequency_get();
-		remote_respond_buf(REMOTE_RESP_OK, (uint8_t *)&freq, 4);
+		remote_respond_buf(REMOTE_RESP_OK, (const uint8_t *)&freq, 4U);
 		break;
 	}
 	case REMOTE_PWR_SET:
@@ -288,7 +288,7 @@ static void remote_packet_process_general(char *packet, const size_t packet_len)
 			remote_respond(REMOTE_RESP_ERR, 0);
 		} else {
 			const bool result = platform_target_set_power(packet[2] == '1');
-			remote_respond(result ? REMOTE_RESP_OK : REMOTE_RESP_ERR, 0);
+			remote_respond(result ? REMOTE_RESP_OK : REMOTE_RESP_ERR, 0U);
 		}
 #else
 		remote_respond(REMOTE_RESP_NOTSUP, 0);
diff --git a/src/target/adiv5_jtag.c b/src/target/adiv5_jtag.c
index 024f40f4c4d..0ccb2d2c19b 100644
--- a/src/target/adiv5_jtag.c
+++ b/src/target/adiv5_jtag.c
@@ -112,7 +112,7 @@ uint32_t adiv5_jtag_raw_access(adiv5_debug_port_s *dp, uint8_t rnw, uint16_t add
 	platform_timeout_set(&timeout, 250);
 	do {
 		uint64_t response;
-		jtag_dev_shift_dr(dp->dev_index, (uint8_t *)&response, (uint8_t *)&request, 35);
+		jtag_dev_shift_dr(dp->dev_index, (uint8_t *)&response, (const uint8_t *)&request, 35);
 		result = response >> 3U;
 		ack = response & 0x07U;
 	} while (!platform_timeout_is_expired(&timeout) && ack == JTAGDP_ACK_WAIT);
diff --git a/src/target/cortexar.c b/src/target/cortexar.c
index 7c313e712fe..30e320e46da 100644
--- a/src/target/cortexar.c
+++ b/src/target/cortexar.c
@@ -1196,7 +1196,7 @@ static bool cortexar_mem_write_slow(
 		offset += 2U;
 	}
 	/* Use the fast path to write as much as possible before doing a slow path fixup at the end */
-	if (!cortexar_mem_write_fast(target, (uint32_t *)(data + offset), (length - offset) >> 2U))
+	if (!cortexar_mem_write_fast(target, (const uint32_t *)(data + offset), (length - offset) >> 2U))
 		return false;
 	const uint8_t remainder = (length - offset) & 3U;
 	/* If the remainder needs at least 2 more bytes write, do this first */
diff --git a/src/target/kinetis.c b/src/target/kinetis.c
index 93464451e6b..c6dabf44462 100644
--- a/src/target/kinetis.c
+++ b/src/target/kinetis.c
@@ -474,9 +474,11 @@ static bool kinetis_flash_cmd_write(target_flash_s *f, target_addr_t dest, const
 	kinetis_flash_s *const kf = (kinetis_flash_s *)f;
 
 	/* Ensure we don't write something horrible over the security byte */
-	if (!f->t->unsafe_enabled && dest <= FLASH_SECURITY_BYTE_ADDRESS && dest + len > FLASH_SECURITY_BYTE_ADDRESS) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
+	if (!f->t->unsafe_enabled && dest <= FLASH_SECURITY_BYTE_ADDRESS && dest + len > FLASH_SECURITY_BYTE_ADDRESS)
 		((uint8_t *)src)[FLASH_SECURITY_BYTE_ADDRESS - dest] = FLASH_SECURITY_BYTE_UNSECURED;
-	}
+#pragma GCC diagnostic pop
 
 	/* Determine write command based on the alignment. */
 	uint8_t write_cmd;
diff --git a/src/target/lpc43xx.c b/src/target/lpc43xx.c
index adbf8b6db08..2e6fe84e19d 100644
--- a/src/target/lpc43xx.c
+++ b/src/target/lpc43xx.c
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2014 Allen Ibara <aibara>
  * Copyright (C) 2015 Gareth McMullin <gareth@blacksphere.co.nz>
- * Copyright (C) 2022 1BitSquared <info@1bitsquared.com>
+ * Copyright (C) 2022-2024 1BitSquared <info@1bitsquared.com>
  * Rewritten by Rachel Mant <git@dragonmux.network>
  *
  * This program is free software: you can redistribute it and/or modify
@@ -908,7 +908,7 @@ static void lpc43x0_spi_write(target_s *const target, const uint16_t command, co
 		target_mem32_write32(target, LPC43xx_GPIO_PORT0_SET, 1U << 6U);
 		lpc43x0_ssp0_setup_command(target, command, address);
 		/* And finally do the meat and potatoes of the transfer */
-		uint8_t *const data = (uint8_t *)buffer;
+		const uint8_t *const data = (const uint8_t *)buffer;
 		for (size_t i = 0; i < length; ++i)
 			lpc43x0_ssp0_transfer(target, data[i]);
 		/* Deselect the Flash */
diff --git a/src/target/lpc_common.c b/src/target/lpc_common.c
index 69e134df5b7..cef2ebeefb9 100644
--- a/src/target/lpc_common.c
+++ b/src/target/lpc_common.c
@@ -2,7 +2,7 @@
  * This file is part of the Black Magic Debug project.
  *
  * Copyright (C) 2015 Gareth McMullin <gareth@blacksphere.co.nz>
- * Copyright (C) 2022-2023 1BitSquared <info@1bitsquared.com>
+ * Copyright (C) 2022-2024 1BitSquared <info@1bitsquared.com>
  * Modified by Rachel Mant <git@dragonmux.network>
  *
  * This program is free software: you can redistribute it and/or modify
@@ -358,13 +358,16 @@ bool lpc_flash_write_magic_vect(target_flash_s *f, target_addr_t dest, const voi
 {
 	if (dest == 0) {
 		/* Fill in the magic vector to allow booting the flash */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 		uint32_t *const vectors = (uint32_t *)src;
+#pragma GCC diagnostic pop
 		uint32_t sum = 0;
 
-		/* compute checksum of first 7 vectors */
+		/* Compute checksum of first 7 vectors */
 		for (size_t i = 0; i < 7U; ++i)
 			sum += vectors[i];
-		/* two's complement is written to 8'th vector */
+		/* Two's complement is written to 8'th vector */
 		vectors[7] = ~sum + 1U;
 	}
 	return lpc_flash_write(f, dest, src, len);
diff --git a/src/target/nxpke04.c b/src/target/nxpke04.c
index 7e1a97ef46b..5bf31fc4cd3 100644
--- a/src/target/nxpke04.c
+++ b/src/target/nxpke04.c
@@ -335,8 +335,11 @@ static bool ke04_flash_write(target_flash_s *f, target_addr_t dest, const void *
 	/* Ensure we don't write something horrible over the security byte */
 	target_s *t = f->t;
 	const uint8_t *data = src;
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	if (!t->unsafe_enabled && dest <= FLASH_SECURITY_BYTE_ADDRESS && dest + len > FLASH_SECURITY_BYTE_ADDRESS)
 		((uint8_t *)data)[FLASH_SECURITY_BYTE_ADDRESS - dest] = FLASH_SECURITY_BYTE_UNSECURED;
+#pragma GCC diagnostic pop
 
 	for (size_t offset = 0; offset < len; offset += KE04_WRITE_LEN) {
 		if (!ke04_command(f->t, CMD_PROGRAM_FLASH, dest + offset, data + offset))
diff --git a/src/target/renesas_ra.c b/src/target/renesas_ra.c
index c26ccbdf0d6..df23ebda0b0 100644
--- a/src/target/renesas_ra.c
+++ b/src/target/renesas_ra.c
@@ -889,7 +889,7 @@ static bool renesas_rv40_flash_write(target_flash_s *const flash, target_addr_t
 		/* Write one chunk */
 		for (size_t i = 0U; i < (write_size / 2U); i++) {
 			/* Copy data from source address to destination */
-			target_mem32_write16(target, RV40_CMD, *(uint16_t *)src);
+			target_mem32_write16(target, RV40_CMD, *(const uint16_t *)src);
 
 			/* 2 bytes of data */
 			src = (const uint8_t *)src + 2U;
diff --git a/src/target/riscv32.c b/src/target/riscv32.c
index b721cd5de55..57e9472c844 100644
--- a/src/target/riscv32.c
+++ b/src/target/riscv32.c
@@ -130,7 +130,7 @@ static void riscv32_regs_write(target_s *const target, const void *const data)
 {
 	/* Grab the hart structure and figure out how many registers need reading out */
 	riscv_hart_s *const hart = riscv_hart_struct(target);
-	riscv32_regs_s *const regs = (riscv32_regs_s *)data;
+	const riscv32_regs_s *const regs = (const riscv32_regs_s *)data;
 	const size_t gprs_count = hart->extensions & RV_ISA_EXT_EMBEDDED ? 16U : 32U;
 	/* Loop through writing out the GPRs, except for the first which is always 0 */
 	for (size_t gpr = 1; gpr < gprs_count; ++gpr) {
diff --git a/src/target/riscv64.c b/src/target/riscv64.c
index d9fd4a898b0..b2fe72051e2 100644
--- a/src/target/riscv64.c
+++ b/src/target/riscv64.c
@@ -78,7 +78,7 @@ static void riscv64_regs_write(target_s *const target, const void *const data)
 {
 	/* Grab the hart structure and figure out how many registers need reading out */
 	riscv_hart_s *const hart = riscv_hart_struct(target);
-	riscv64_regs_s *const regs = (riscv64_regs_s *)data;
+	const riscv64_regs_s *const regs = (const riscv64_regs_s *)data;
 	const size_t gprs_count = hart->extensions & RV_ISA_EXT_EMBEDDED ? 16U : 32U;
 	/* Loop through writing out the GPRs, except for the first which is always 0 */
 	for (size_t gpr = 1; gpr < gprs_count; ++gpr) {
diff --git a/src/target/semihosting.c b/src/target/semihosting.c
index 8c5b8999596..1575064cfb5 100644
--- a/src/target/semihosting.c
+++ b/src/target/semihosting.c
@@ -403,7 +403,10 @@ int32_t semihosting_open(target_s *const target, const semihosting_s *const requ
 
 	const int32_t result = open(file_name, native_open_mode | O_NOCTTY, 0644);
 	target->tc->gdb_errno = semihosting_errno();
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	free((void *)file_name);
+#pragma GCC diagnostic pop
 #else
 	gdb_putpacket_f("Fopen,%08" PRIX32 "/%08" PRIX32 ",%08" PRIX32 ",%08X", file_name_taddr, file_name_length + 1U,
 		open_mode, 0644U);
@@ -451,13 +454,13 @@ int32_t semihosting_read(target_s *const target, const semihosting_s *const requ
 		target_mem32_write(target, buf_taddr, semihosting_features + semihosting_features_offset, amount);
 		semihosting_features_offset += amount;
 		/* Return how much was left from what we transferred */
-		return buf_len - amount;
+		return (int32_t)(buf_len - amount);
 	}
 
 	const int32_t fd = request->params[0] - 1;
 	const int32_t result = semihosting_remote_read(target, fd, buf_taddr, buf_len);
 	if (result >= 0)
-		return buf_len - result;
+		return (int32_t)(buf_len - result);
 	return result;
 }
 
@@ -550,13 +553,19 @@ int32_t semihosting_rename(target_s *const target, const semihosting_s *const re
 		return -1;
 	const char *const new_file_name = semihosting_read_string(target, request->params[2], request->params[3]);
 	if (new_file_name == NULL) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 		free((void *)old_file_name);
+#pragma GCC diagnostic pop
 		return -1;
 	}
 	const int32_t result = rename(old_file_name, new_file_name);
 	target->tc->gdb_errno = semihosting_errno();
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	free((void *)old_file_name);
 	free((void *)new_file_name);
+#pragma GCC diagnostic pop
 	return result;
 #else
 	gdb_putpacket_f("Frename,%08" PRIX32 "/%08" PRIX32 ",%08" PRIX32 "/%08" PRIX32, request->params[0],
@@ -573,7 +582,10 @@ int32_t semihosting_remove(target_s *const target, const semihosting_s *const re
 		return -1;
 	const int32_t result = remove(file_name);
 	target->tc->gdb_errno = semihosting_errno();
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wcast-qual"
 	free((void *)file_name);
+#pragma GCC diagnostic pop
 	return result;
 #else
 	gdb_putpacket_f("Funlink,%08" PRIX32 "/%08" PRIX32, request->params[0], request->params[1] + 1U);
diff --git a/src/target/spi.c b/src/target/spi.c
index ad4c789a090..523fef9a2cd 100644
--- a/src/target/spi.c
+++ b/src/target/spi.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the Black Magic Debug project.
  *
- * Copyright (C) 2023 1BitSquared <info@1bitsquared.com>
+ * Copyright (C) 2023-2024 1BitSquared <info@1bitsquared.com>
  * Written by Rachel Mant <git@dragonmux.network>
  * All rights reserved.
  *
@@ -80,7 +80,7 @@ void bmp_spi_write(const spi_bus_e bus, const uint8_t device, const uint16_t com
 	/* Setup the transaction */
 	bmp_spi_setup_xfer(bus, device, command, address);
 	/* Now write out back the data requested */
-	uint8_t *const data = (uint8_t *const)buffer;
+	const uint8_t *const data = (const uint8_t *)buffer;
 	for (size_t i = 0; i < length; ++i)
 		/* Do a write to read */
 		platform_spi_xfer(bus, data[i]);