diff --git a/lib/pbl/CMakeLists.txt b/lib/pbl/CMakeLists.txt
index 58cd345..0323ab9 100644
--- a/lib/pbl/CMakeLists.txt
+++ b/lib/pbl/CMakeLists.txt
@@ -1,8 +1,8 @@
 cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
 project(pbl C)
 
-set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_RELEASE} -Wall")
-set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Wall -O3")
+set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_RELEASE} -Wall -Wno-sign-compare")
+set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -Wall -Wno-sign-compare -O3")
 
 option(PBL_WITH_TESTS "Enable building test programs" ON)
 
diff --git a/src/machinery/tiger.c b/src/machinery/tiger.c
index 02c0138..a42d544 100644
--- a/src/machinery/tiger.c
+++ b/src/machinery/tiger.c
@@ -710,8 +710,10 @@ void tiger(const char *str, t_word length, t_res res, char pad)
 
 void tiger_2_chunk(const char *str1, const char *str2, t_word length, t_res res1, t_res res2)
 {
+#if defined(USE_BIG_ENDIAN) || defined(FORCE_ALIGNMENT)
     t_block tmp1;
     t_block tmp2;
+#endif
     const char * end = str1 + (length&(-64));
 
     while(str1<end)
@@ -746,6 +748,9 @@ void tiger_2_last_chunk (const char *str1, const char *str2, t_word length, t_wo
     t_block tmp2;
     endianvars_2;
 
+    (void)reallength1;
+    (void)reallength2;
+
     i=length & 63;
     //Padding on last block
     //add 0x01 afterwards.
@@ -803,8 +808,10 @@ void tiger_2(const char *str1, const char *str2, t_word length, t_res res1, t_re
 #ifdef __SSE2__
 void tiger_sse2_chunk(const char *str1, const char *str2, t_word length, t_res res1, t_res res2)
 {
+#ifdef FORCE_ALIGNMENT
     t_block tmp1;
     t_block tmp2;
+#endif
     const char * end = str1 + length;
 
     while(str1<end)
diff --git a/src/main/damerau_levenshtein.c b/src/main/damerau_levenshtein.c
index 1aa100f..2bdd150 100644
--- a/src/main/damerau_levenshtein.c
+++ b/src/main/damerau_levenshtein.c
@@ -90,6 +90,9 @@ static void insert_pair (PblMap* parMap, Character parKey, int parValue) {
 		sizeof(parValue)
 	);
 	assert(0 <= retval);
+#ifdef NDEBUG
+	(void)retval;
+#endif
 }
 
 static int get_value (PblMap* parMap, Character parKey) {
@@ -177,7 +180,7 @@ int damerau_levenshtein_with_size (
 	if (0 == parTargetLen)
 		return parSourceLen * parDeleteCost;
 
-	const int table_length = parSourceLen * parTargetLen;
+	const size_t table_length = parSourceLen * parTargetLen;
 	table = malloc(sizeof(int) * table_length);
 	memset(table, 0, sizeof(int) * table_length);
 
@@ -197,7 +200,8 @@ int damerau_levenshtein_with_size (
 	insert_pair(sourceIndexByCharacter, source_char_0, 0);
 
 	assert(source = source_index_1);
-	for (i = 1; i < parSourceLen; ++i) {
+	assert(parSourceLen <= INT_MAX);
+	for (i = 1; i < (int)parSourceLen; ++i) {
 		source_char = utf8_advance(&source, source_end);
 		delete_distance = table[i - 1 + 0 * parSourceLen] + parDeleteCost;
 		insert_distance = (i + 1) * parDeleteCost + parInsertCost;
@@ -209,7 +213,8 @@ int damerau_levenshtein_with_size (
 	}
 
 	assert(target == target_index_1);
-	for (j = 1; j < parTargetLen; ++j) {
+	assert(parTargetLen <= INT_MAX);
+	for (j = 1; j < (int)parTargetLen; ++j) {
 		target_char = utf8_advance(&target, target_end);
 		delete_distance = (j + 1) * parInsertCost + parDeleteCost;
 		insert_distance = table[0 + (j - 1) * parSourceLen] + parInsertCost;
@@ -221,11 +226,13 @@ int damerau_levenshtein_with_size (
 	}
 
 	source = source_index_1;
-	for (i = 1; i < parSourceLen; ++i) {
+	assert(parSourceLen <= INT_MAX);
+	for (i = 1; i < (int)parSourceLen; ++i) {
 		source_char = utf8_advance(&source, source_end);
 		maxSourceLetterMatchIndex = (source_char == target_char_0 ? 0 : -1);
 		target = target_index_1;
-		for (j = 1; j < parTargetLen; ++j) {
+		assert(parTargetLen <= INT_MAX);
+		for (j = 1; j < (int)parTargetLen; ++j) {
 			target_char = utf8_advance(&target, target_end);
 			candidateSwapIndex = get_value(sourceIndexByCharacter, target_char);
 			j_swap = maxSourceLetterMatchIndex;
diff --git a/src/main/findactions.c b/src/main/findactions.c
index e8fb5aa..a2790db 100644
--- a/src/main/findactions.c
+++ b/src/main/findactions.c
@@ -74,7 +74,6 @@ void free_actions (char** parActions, size_t parCount) {
 static void foreach_dir (void(*parAction)(const char*, ActionList*), ActionList* parList) {
 	DIR* d;
 	struct dirent* dir;
-	size_t z;
 	struct stat st;
 	char* path_buff;
 	size_t path_buff_length;
@@ -127,6 +126,7 @@ static void foreach_dir (void(*parAction)(const char*, ActionList*), ActionList*
 }
 
 static void increase_actionlist (const char* parName, ActionList* parList) {
+	(void)parName;
 	++parList->count;
 }
 
diff --git a/src/main/main.c b/src/main/main.c
index deeb75e..f961f0b 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -127,7 +127,7 @@ int main (int parArgc, char* parArgv[]) {
 
 	argv = malloc(sizeof(char*) * (parArgc - 1 + 1));
 	argv[0] = action_path;
-	for (z = 2; z < parArgc; ++z) {
+	for (z = 2; z < (size_t)parArgc; ++z) {
 		argv[z - 1] = parArgv[z];
 	}
 	argv[parArgc - 1] = NULL;