diff --git a/dlls/ntdll/loader.c b/dlls/ntdll/loader.c
index 3a28b414ea4..0455df43dbe 100644
--- a/dlls/ntdll/loader.c
+++ b/dlls/ntdll/loader.c
@@ -57,7 +57,7 @@ WINE_DECLARE_DEBUG_CHANNEL(imports);
 
 typedef DWORD (CALLBACK *DLLENTRYPROC)(HMODULE,DWORD,LPVOID);
 
-static int process_detaching = 0;  /* set on process detach to avoid deadlocks with thread detach */
+static BOOL process_detaching = FALSE;  /* set on process detach to avoid deadlocks with thread detach */
 static int free_lib_count;   /* recursion depth of LdrUnloadDll calls */
 
 static const char * const reason_names[] =
@@ -127,7 +127,7 @@ static inline void *get_rva( HMODULE module, DWORD va )
 }
 
 /* check whether the file name contains a path */
-static inline int contains_path( LPCWSTR name )
+static inline BOOL contains_path( LPCWSTR name )
 {
     return ((*name && (name[1] == ':')) || strchrW(name, '/') || strchrW(name, '\\'));
 }
@@ -2391,7 +2391,7 @@ BOOLEAN WINAPI RtlDllShutdownInProgress(void)
 void WINAPI LdrShutdownProcess(void)
 {
     TRACE("()\n");
-    process_detaching = 1;
+    process_detaching = TRUE;
     process_detach();
 }
 
diff --git a/dlls/ntdll/nt.c b/dlls/ntdll/nt.c
index 8a53d036a44..c9499d6c94e 100644
--- a/dlls/ntdll/nt.c
+++ b/dlls/ntdll/nt.c
@@ -850,7 +850,7 @@ static inline void do_cpuid(unsigned int ax, unsigned int *p)
 }
 
 /* From xf86info havecpuid.c 1.11 */
-static inline int have_cpuid(void)
+static inline BOOL have_cpuid(void)
 {
 #ifdef __i386__
 	unsigned int f1, f2;
@@ -868,16 +868,16 @@ static inline int have_cpuid(void)
                 : "ir" (0x00200000));
 	return ((f1^f2) & 0x00200000) != 0;
 #elif defined(__x86_64__)
-        return 1;
+        return TRUE;
 #else
-        return 0;
+        return FALSE;
 #endif
 }
 
 /* Detect if a SSE2 processor is capable of Denormals Are Zero (DAZ) mode.
  *
  * This function assumes you have already checked for SSE2/FXSAVE support. */
-static inline int have_sse_daz_mode(void)
+static inline BOOL have_sse_daz_mode(void)
 {
 #ifdef __i386__
     typedef struct DECLSPEC_ALIGN(16) _M128A {
@@ -913,7 +913,7 @@ static inline int have_sse_daz_mode(void)
 
     return (state->MxCsr_Mask & (1 << 6)) >> 6;
 #else /* all x86_64 processors include SSE2 with DAZ mode */
-    return 1;
+    return TRUE;
 #endif
 }
 
diff --git a/dlls/ntdll/server.c b/dlls/ntdll/server.c
index 9b3aeef14cc..f396dd5b379 100644
--- a/dlls/ntdll/server.c
+++ b/dlls/ntdll/server.c
@@ -814,7 +814,7 @@ static inline unsigned int handle_to_index( HANDLE handle, unsigned int *entry )
  *
  * Caller must hold fd_cache_section.
  */
-static int add_fd_to_cache( HANDLE handle, int fd, enum server_fd_type type,
+static BOOL add_fd_to_cache( HANDLE handle, int fd, enum server_fd_type type,
                             unsigned int access, unsigned int options )
 {
     unsigned int entry, idx = handle_to_index( handle, &entry );
@@ -823,7 +823,7 @@ static int add_fd_to_cache( HANDLE handle, int fd, enum server_fd_type type,
     if (entry >= FD_CACHE_ENTRIES)
     {
         FIXME( "too many allocated handles, not caching %p\n", handle );
-        return 0;
+        return FALSE;
     }
 
     if (!fd_cache[entry])  /* do we need to allocate a new block of entries? */
@@ -833,7 +833,7 @@ static int add_fd_to_cache( HANDLE handle, int fd, enum server_fd_type type,
         {
             void *ptr = wine_anon_mmap( NULL, FD_CACHE_BLOCK_SIZE * sizeof(struct fd_cache_entry),
                                         PROT_READ | PROT_WRITE, 0 );
-            if (ptr == MAP_FAILED) return 0;
+            if (ptr == MAP_FAILED) return FALSE;
             fd_cache[entry] = ptr;
         }
     }
@@ -843,7 +843,7 @@ static int add_fd_to_cache( HANDLE handle, int fd, enum server_fd_type type,
     fd_cache[entry][idx].access = access;
     fd_cache[entry][idx].options = options;
     if (prev_fd != -1) close( prev_fd );
-    return 1;
+    return TRUE;
 }
 
 
@@ -1025,12 +1025,12 @@ int server_pipe( int fd[2] )
 {
     int ret;
 #ifdef HAVE_PIPE2
-    static int have_pipe2 = 1;
+    static BOOL have_pipe2 = TRUE;
 
     if (have_pipe2)
     {
         if (!(ret = pipe2( fd, O_CLOEXEC ))) return ret;
-        if (errno == ENOSYS || errno == EINVAL) have_pipe2 = 0;  /* don't try again */
+        if (errno == ENOSYS || errno == EINVAL) have_pipe2 = FALSE;  /* don't try again */
     }
 #endif
     if (!(ret = pipe( fd )))
@@ -1049,7 +1049,7 @@ int server_pipe( int fd[2] )
  */
 static void start_server(void)
 {
-    static int started;  /* we only try once */
+    static BOOL started;  /* we only try once */
     char *argv[3];
     static char wineserver[] = "server/wineserver";
     static char debug[] = "-d";
@@ -1071,7 +1071,7 @@ static void start_server(void)
         status = WIFEXITED(status) ? WEXITSTATUS(status) : 1;
         if (status == 2) return;  /* server lock held by someone else, will retry later */
         if (status) exit(status);  /* server failed */
-        started = 1;
+        started = TRUE;
     }
 }
 
@@ -1428,7 +1428,7 @@ NTSTATUS server_init_process_done(void)
  */
 size_t server_init_thread( void *entry_point )
 {
-    static const int is_win64 = (sizeof(void *) > sizeof(int));
+    static const BOOL is_win64 = (sizeof(void *) > sizeof(int));
     const char *arch = getenv( "WINEARCH" );
     int ret;
     int reply_pipe[2];
diff --git a/dlls/ntdll/signal_x86_64.c b/dlls/ntdll/signal_x86_64.c
index 8bcf71b9add..b28cb99e4fb 100644
--- a/dlls/ntdll/signal_x86_64.c
+++ b/dlls/ntdll/signal_x86_64.c
@@ -814,7 +814,7 @@ static const char *dwarf_reg_names[NB_FRAME_REGS] =
 /* 33-40 */ "%st0", "%st1", "%st2", "%st3", "%st4", "%st5", "%st6", "%st7"
 };
 
-static int valid_reg( ULONG_PTR reg )
+static BOOL valid_reg( ULONG_PTR reg )
 {
     if (reg >= NB_FRAME_REGS) FIXME( "unsupported reg %lx\n", reg );
     return (reg < NB_FRAME_REGS);
@@ -1383,7 +1383,7 @@ static inline void *get_signal_stack(void)
  *
  * Check if pointer is inside the signal stack.
  */
-static inline int is_inside_signal_stack( void *ptr )
+static inline BOOL is_inside_signal_stack( void *ptr )
 {
     return ((char *)ptr >= (char *)get_signal_stack() &&
             (char *)ptr < (char *)get_signal_stack() + signal_stack_size);
diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c
index e8a8b50a2da..e438eaa4775 100644
--- a/dlls/ntdll/virtual.c
+++ b/dlls/ntdll/virtual.c
@@ -135,7 +135,7 @@ static void *user_space_limit;
 static void *working_set_limit;
 static void *address_space_start = (void *)0x10000;
 #endif  /* __i386__ */
-static const int is_win64 = (sizeof(void *) > sizeof(int));
+static const BOOL is_win64 = (sizeof(void *) > sizeof(int));
 
 #define ROUND_ADDR(addr,mask) \
    ((void *)((UINT_PTR)(addr) & ~(UINT_PTR)(mask)))
@@ -151,8 +151,8 @@ static const int is_win64 = (sizeof(void *) > sizeof(int));
 static HANDLE virtual_heap;
 static void *preload_reserve_start;
 static void *preload_reserve_end;
-static int use_locks;
-static int force_exec_prot;  /* whether to force PROT_EXEC on all PROT_READ mmaps */
+static BOOL use_locks;
+static BOOL force_exec_prot;  /* whether to force PROT_EXEC on all PROT_READ mmaps */
 
 
 /***********************************************************************
@@ -410,7 +410,7 @@ static void remove_reserved_area( void *addr, size_t size )
  *
  * Check if an address range goes beyond a given limit.
  */
-static inline int is_beyond_limit( const void *addr, size_t size, const void *limit )
+static inline BOOL is_beyond_limit( const void *addr, size_t size, const void *limit )
 {
     return (addr >= limit || (const char *)addr + size > (const char *)limit);
 }
@@ -1452,7 +1452,7 @@ void virtual_init(void)
  */
 void virtual_init_threading(void)
 {
-    use_locks = 1;
+    use_locks = TRUE;
 }