diff --git a/src/gamecode/laws.c b/src/gamecode/laws.c
index 3b332fec7..3e7ca3595 100755
--- a/src/gamecode/laws.c
+++ b/src/gamecode/laws.c
@@ -1327,7 +1327,7 @@ static void do_contact(region * r)
   }
 }
 
-void do_enter(struct region *r, int is_final_attempt)
+void do_enter(struct region *r, bool is_final_attempt)
 {
   unit **uptr;
 
diff --git a/src/gamecode/laws.h b/src/gamecode/laws.h
index 3cc5882e5..7f96db564 100755
--- a/src/gamecode/laws.h
+++ b/src/gamecode/laws.h
@@ -56,7 +56,7 @@ extern "C" {
   extern void restack_units(void);
   extern void update_long_order(struct unit *u);
   extern void sinkships(struct region * r);
-  extern void do_enter(struct region *r, int is_final_attempt);
+  extern void do_enter(struct region *r, bool is_final_attempt);
 
   extern int password_cmd(struct unit *u, struct order *ord);
   extern int banner_cmd(struct unit *u, struct order *ord);
diff --git a/src/kernel/config.c b/src/kernel/config.c
index 08970f71b..a6db38377 100644
--- a/src/kernel/config.c
+++ b/src/kernel/config.c
@@ -1403,13 +1403,13 @@ param_t findparam_ex(const char *s, const struct locale * lang)
   return (result == P_BUILDING) ? P_GEBAEUDE : result;
 }
 
-int isparam(const char *s, const struct locale * lang, param_t param)
+bool isparam(const char *s, const struct locale * lang, param_t param)
 {
   if (s[0]>'@') {
     param_t p = (param==P_GEBAEUDE) ? findparam_ex(s, lang) : findparam(s, lang);
     return p==param;
   }
-  return 0;
+  return false;
 }
 
 param_t getparam(const struct locale * lang)
diff --git a/src/kernel/config.h b/src/kernel/config.h
index e85325bc1..75be214e0 100644
--- a/src/kernel/config.h
+++ b/src/kernel/config.h
@@ -174,7 +174,7 @@ extern "C" {
 
   param_t findparam(const char *s, const struct locale *lang);
   param_t findparam_ex(const char *s, const struct locale * lang);
-  int isparam(const char *s, const struct locale * lang, param_t param);
+  bool isparam(const char *s, const struct locale * lang, param_t param);
   param_t getparam(const struct locale *lang);
 
   extern int getid(void);
diff --git a/src/kernel/move.c b/src/kernel/move.c
index 7eed52d5f..80bdfbd5a 100644
--- a/src/kernel/move.c
+++ b/src/kernel/move.c
@@ -633,7 +633,7 @@ static bool is_freezing(const unit * u)
 #define SA_NO_INSECT -1
 #define SA_NO_COAST -2
 
-static int is_ship_allowed(struct ship *sh, const region * r)
+static bool is_ship_allowed(struct ship *sh, const region * r)
 {
   int c = 0;
   static const building_type *bt_harbour = NULL;
diff --git a/src/kernel/order.c b/src/kernel/order.c
index 9004fd4db..d7105e8eb 100644
--- a/src/kernel/order.c
+++ b/src/kernel/order.c
@@ -373,7 +373,7 @@ order *parse_order(const char *s, const struct locale * lang)
  * \return true if the order is long
  * \sa is_exclusive(), is_repeated(), is_persistent()
  */
-int is_repeated(const order * ord)
+bool is_repeated(const order * ord)
 {
   keyword_t kwd = ORD_KEYWORD(ord);
   const struct locale *lang = ORD_LOCALE(ord);
@@ -439,7 +439,7 @@ int is_repeated(const order * ord)
  * \return true if the order is long
  * \sa is_exclusive(), is_repeated(), is_persistent()
  */
-int is_exclusive(const order * ord)
+bool is_exclusive(const order * ord)
 {
   keyword_t kwd = ORD_KEYWORD(ord);
   const struct locale *lang = ORD_LOCALE(ord);
@@ -500,11 +500,11 @@ int is_exclusive(const order * ord)
  * \return true if the order is long
  * \sa is_exclusive(), is_repeated(), is_persistent()
  */
-int is_long(const order * ord)
+bool is_long(const order * ord)
 {
   keyword_t kwd = ORD_KEYWORD(ord);
   const struct locale *lang = ORD_LOCALE(ord);
-  int result = 0;
+  bool result = false;
 
   switch (kwd) {
   case K_CAST:
@@ -550,7 +550,7 @@ int is_long(const order * ord)
     parser_popstate();
     break;
   default:
-    result = 0;
+    result = false;
   }
   return result;
 }
@@ -564,7 +564,7 @@ int is_long(const order * ord)
  * \return true if the order is persistent
  * \sa is_exclusive(), is_repeated(), is_persistent()
  */
-int is_persistent(const order * ord)
+bool is_persistent(const order * ord)
 {
   keyword_t kwd = ORD_KEYWORD(ord);
   int persist = ord->_persistent != 0;
diff --git a/src/kernel/order.h b/src/kernel/order.h
index 9e0ebeef5..6e2159687 100644
--- a/src/kernel/order.h
+++ b/src/kernel/order.h
@@ -51,10 +51,10 @@ extern "C" {
   extern keyword_t get_keyword(const order * ord);
   extern void set_order(order ** destp, order * src);
   extern char *getcommand(const order * ord);
-  extern int is_persistent(const order * ord);
-  extern int is_exclusive(const order * ord);
-  extern int is_repeated(const order * ord);
-  extern int is_long(const order * ord);
+  extern bool is_persistent(const order * ord);
+  extern bool is_exclusive(const order * ord);
+  extern bool is_repeated(const order * ord);
+  extern bool is_long(const order * ord);
 
   extern char *write_order(const order * ord, char *buffer, size_t size);
 
diff --git a/src/kernel/region.c b/src/kernel/region.c
index bfaaab804..bdd16de12 100644
--- a/src/kernel/region.c
+++ b/src/kernel/region.c
@@ -817,17 +817,17 @@ bool r_isforest(const region * r)
   return false;
 }
 
-int is_coastregion(region * r)
+bool is_coastregion(region * r)
 {
   direction_t i;
   int res = 0;
 
-  for (i = 0; i < MAXDIRECTIONS; i++) {
+  for (i = 0; !res && i < MAXDIRECTIONS; i++) {
     region *rn = rconnect(r, i);
     if (rn && fval(rn->terrain, SEA_REGION))
       res++;
   }
-  return res;
+  return res!=0;
 }
 
 int rpeasants(const region * r)
diff --git a/src/kernel/region.h b/src/kernel/region.h
index 88764586a..2cdd3dd95 100644
--- a/src/kernel/region.h
+++ b/src/kernel/region.h
@@ -210,7 +210,7 @@ extern "C" {
   short rroad(const struct region *r, direction_t d);
   void rsetroad(struct region *r, direction_t d, short value);
 
-  int is_coastregion(struct region *r);
+  bool is_coastregion(struct region *r);
 
   int rtrees(const struct region *r, int ageclass);
   enum {