diff --git a/components/common/uuid/uuid.c b/components/common/uuid/uuid.c
index 6f8b2ec..ab8a448 100644
--- a/components/common/uuid/uuid.c
+++ b/components/common/uuid/uuid.c
@@ -46,7 +46,7 @@
 				if (canonical_form[i] != '-') return 0;
 			}
 			else {
-				if (!isxdigit(canonical_form[i])) return 0;
+				if (!isxdigit((int)canonical_form[i])) return 0;
 			}
 		}
 	}
diff --git a/components/rpc/mm_communicate/endpoint/sp/mm_communicate_call_ep.c b/components/rpc/mm_communicate/endpoint/sp/mm_communicate_call_ep.c
index 93aa0f4..9db9288 100644
--- a/components/rpc/mm_communicate/endpoint/sp/mm_communicate_call_ep.c
+++ b/components/rpc/mm_communicate/endpoint/sp/mm_communicate_call_ep.c
@@ -38,7 +38,6 @@
 				 EFI_MM_COMMUNICATE_HEADER *header,
 				 size_t buffer_size)
 {
-	rpc_status_t rpc_status = TS_RPC_ERROR_INTERNAL;
 	struct mm_service_call_req call_req = { 0 };
 	int32_t result = 0;
 
diff --git a/components/service/locator/service_name.c b/components/service/locator/service_name.c
index 0999787..440db9b 100644
--- a/components/service/locator/service_name.c
+++ b/components/service/locator/service_name.c
@@ -180,7 +180,7 @@
 			size_t digit_index = fields.instance_pos + fields.instance_len - 1 - i;
 			char digit = sn[digit_index];
 
-			if (isdigit(digit)) {
+			if (isdigit((int)digit)) {
 
 			   instance += ((digit - '0') * multiplier);
 			   multiplier *= 10;
diff --git a/components/service/spm_test/sp.c b/components/service/spm_test/sp.c
index fa9c7ea..01cc7d2 100644
--- a/components/service/spm_test/sp.c
+++ b/components/service/spm_test/sp.c
@@ -281,10 +281,9 @@
 	    sp_msg.args.args64[3] == 0xBC &&sp_msg.args.args64[4] == 0xCD) {
 		return_ok(msg);
 	} else {
-		DMSG("Failed SP communication %x %x %x %x",
-		     sp_msg.args.args64[1],
-		     sp_msg.args.args64[2], sp_msg.args.args64[3],
-		     sp_msg.args.args64[4]);
+		DMSG("Failed SP communication %lx %lx %lx %lx",
+		     sp_msg.args.args64[1], sp_msg.args.args64[2],
+		     sp_msg.args.args64[3], sp_msg.args.args64[4]);
 
 		return_error(ERR_SP_COMMUNICATION, msg);
 	}
@@ -374,7 +373,6 @@
 static void test_mem_relinquish(struct ffa_direct_msg *msg)
 {
 	ffa_result res = FFA_OK;
-	struct sp_memory_descriptor descriptor = {0};
 	uint64_t handle = 0;
 	uint16_t endpoint_id = 0;
 	struct sp_memory_transaction_flags flags = {
@@ -388,7 +386,6 @@
 	ffa_id_get(&endpoint_id);
 	handle = (uint64_t)msg->args.args64[1] |
 		 (((uint64_t)msg->args.args64[2]) << 32);
-	descriptor.tag = 0;
 
 	res = sp_memory_relinquish(handle, &endpoint_id, 1, &flags);
 	if (res) {