diff --git a/source/src/audiomanager.cpp b/source/src/audiomanager.cpp
index 44b269f8..8d8e7372 100644
--- a/source/src/audiomanager.cpp
+++ b/source/src/audiomanager.cpp
@@ -929,7 +929,7 @@ void deletemapsoundslot(int *n, char *opt) // delete mapsound slot - only if unu
         { // delete entity
             deleted_ents.add(e);
             deletesoundentity(e);
-            memset(&e, 0, sizeof(persistent_entity));
+            memset((void *)&e, 0, sizeof(persistent_entity));
             e.type = NOTUSED;
             deld++;
         }
diff --git a/source/src/console.cpp b/source/src/console.cpp
index 7f1b9bca..77465026 100644
--- a/source/src/console.cpp
+++ b/source/src/console.cpp
@@ -633,7 +633,7 @@ bool textinputbuffer::say(const char *c)
     int buflen = (int)strlen(buf), txtlen = (int)strlen(txt);
     if(txtlen && buflen < maxlen() &&  buflen + txtlen < (int)sizeof(buf))
     {
-        if(pos < 0) strncpy(buf + buflen, txt, txtlen);
+        if(pos < 0) memcpy(buf + buflen, txt, txtlen);
         else
         {
             memmove(&buf[pos + txtlen], &buf[pos], buflen - pos);
diff --git a/source/src/http.cpp b/source/src/http.cpp
index a8e85f03..48e2555f 100644
--- a/source/src/http.cpp
+++ b/source/src/http.cpp
@@ -328,7 +328,7 @@ int httpget::get(const char *url1, uint timeout, uint totaltimeout, int range, b
     if(gzipped)
     {
         z_stream zs;
-        memset(&zs, 0, sizeof(zs));
+        memset((void *)&zs, 0, sizeof(zs));
         if(inflateInit2(&zs, 15 + 32) == Z_OK)
         {
             zs.next_in = (Bytef*)content->getbuf();
diff --git a/source/src/rendermodel.cpp b/source/src/rendermodel.cpp
index 9c218630..b030cf86 100644
--- a/source/src/rendermodel.cpp
+++ b/source/src/rendermodel.cpp
@@ -179,7 +179,7 @@ void deletemapmodelslot(int *n, char *opt) // delete mapmodel slot - only if unu
         if(e.attr2 == *n)
         { // delete entity
             deleted_ents.add(e);
-            memset(&e, 0, sizeof(persistent_entity));
+            memset((void *)&e, 0, sizeof(persistent_entity));
             e.type = NOTUSED;
             deld++;
         }
diff --git a/source/src/scoreboard.cpp b/source/src/scoreboard.cpp
index 27114283..b1cc6dd2 100644
--- a/source/src/scoreboard.cpp
+++ b/source/src/scoreboard.cpp
@@ -420,7 +420,7 @@ void renderscores(void *menu, bool init)
 
 #define MAXJPGCOM 65533  // maximum JPEG comment length
 
-static void addstr(char *&dest, const char *end, const char *src) { size_t l = strlen(src); if(dest + l < end) copystring(dest, src, l + 1), dest += l; }
+static void addstr(char *&dest, const char *end, const char *src) { size_t l = strlen(src); if(dest + l < end) memcpy(dest, src, l + 1), dest += l; }
 
 const char *asciiscores(bool destjpg)
 {
diff --git a/source/src/stream.cpp b/source/src/stream.cpp
index 829deb3f..cfe5c4df 100644
--- a/source/src/stream.cpp
+++ b/source/src/stream.cpp
@@ -272,6 +272,20 @@ const char *stream_capabilities()
     #endif
 }
 
+#if !defined(WIN32)
+int readdir_r_(DIR *d, struct dirent *b, struct dirent **de)
+{
+    #ifdef __USE_POSIX
+    #pragma GCC diagnostic push
+    #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+    #endif
+    return readdir_r(d, b, de);
+    #ifdef __USE_POSIX
+    #pragma GCC diagnostic pop
+    #endif
+}
+#endif
+
 bool listsubdir(const char *dir, vector<char *> &subdirs)
 {
     #if defined(WIN32)
@@ -293,7 +307,7 @@ bool listsubdir(const char *dir, vector<char *> &subdirs)
     if(d)
     {
         struct dirent *de, b;
-        while(!readdir_r(d, &b, &de) && de != NULL)
+        while(!readdir_r_(d, &b, &de) && de != NULL)
         {
         #ifdef _DIRENT_HAVE_D_TYPE
             if(de->d_type == DT_DIR && de->d_name[0] != '.') subdirs.add(newstring(de->d_name));
@@ -361,7 +375,7 @@ bool listdir(const char *dir, const char *ext, vector<char *> &files)
     if(d)
     {
         struct dirent *de, b;
-        while(!readdir_r(d, &b, &de) && de != NULL)
+        while(!readdir_r_(d, &b, &de) && de != NULL)
         {
             bool isreg = false;
         #ifdef _DIRENT_HAVE_D_TYPE
diff --git a/source/src/tools.h b/source/src/tools.h
index bd35136a..953c0ddc 100644
--- a/source/src/tools.h
+++ b/source/src/tools.h
@@ -119,6 +119,7 @@ typedef char string[MAXSTRLEN];
 
 #define vformatstring(d,last,fmt) { va_list ap; va_start(ap, last); vformatstring_(d, fmt, ap); va_end(ap); }
 inline void vformatstring_(char* d, const char* fmt, va_list v, int len = MAXSTRLEN) { _vsnprintf(d, len, fmt, v); d[len - 1] = 0; }
+//#pragma GCC diagnostic ignored "-Wstringop-truncation" // moved to makefile, because it doesn't work from precompiled header
 inline char *copystring(char *d, const char *s, size_t len = MAXSTRLEN) { strncpy(d, s, len); d[len-1] = 0; return d; }
 inline char *concatstring(char *d, const char *s, size_t len = MAXSTRLEN) { size_t used = strlen(d); return used < len ? copystring(d+used, s, len-used) : d; }
 extern char *concatformatstring(char *d, const char *s, ...) PRINTFARGS(2, 3);
diff --git a/source/src/world.cpp b/source/src/world.cpp
index 05448862..3c73309f 100644
--- a/source/src/world.cpp
+++ b/source/src/world.cpp
@@ -478,7 +478,7 @@ void deleteentity(char *ns)
     if(t == SOUND) deletesoundentity(e);
     conoutf("deleted entity #%d (%s)", n, entnames[e.type]);
     deleted_ents.add(e);
-    memset(&e, 0, sizeof(persistent_entity));
+    memset((void *)&e, 0, sizeof(persistent_entity));
     e.type = NOTUSED;
     if(t == LIGHT) calclight();
     unsavededits++;
@@ -751,7 +751,7 @@ bool empty_world(int factor, bool force)    // main empty world creation routine
         clearheaderextras();
         unsavededits = oldunsavededits;
     }
-    strncpy(hdr.head, "ACMP", 4);
+    memcpy(hdr.head, "ACMP", 4);
     hdr.version = MAPVERSION;
     hdr.headersize = sizeof(header);
     hdr.sfactor = sfactor;
diff --git a/source/src/worldio.cpp b/source/src/worldio.cpp
index 6f9d74d9..6c212af5 100644
--- a/source/src/worldio.cpp
+++ b/source/src/worldio.cpp
@@ -741,6 +741,7 @@ void save_world(char *mname, bool skipoptimise, bool addcomfort)
     }
 
     // update (and fix) map header
+    memcpy(hdr.head, "ACMP", 4); // ensure map now declares itself as an AssaultCube map, even if imported as CUBE
     hdr.version = MAPVERSION;
     hdr.headersize = sizeof(header);
     hdr.timestamp = (int) time(NULL);
@@ -1046,7 +1047,7 @@ int load_world(char *mname)        // still supports all map formats that have e
     loopi(hdr.numents)
     {
         entity &e = ents.add();
-        memcpy(&e, &tempents[i], sizeof(persistent_entity));
+        memcpy((void *)&e, &tempents[i], sizeof(persistent_entity));
         e.spawned = false;
     }
     delete[] tempents;
@@ -1327,7 +1328,7 @@ struct xmap
     void restoreent(int i)
     {
         entity &e = ::ents.add();
-        memcpy(&e, &ents[i], sizeof(persistent_entity));
+        memcpy((void *)&e, &ents[i], sizeof(persistent_entity));
         e.spawned = true;
     }