diff --git a/lib/easy.c b/lib/easy.c
index a0704b0ed3..ab34e1499c 100644
--- a/lib/easy.c
+++ b/lib/easy.c
@@ -605,7 +605,7 @@ static CURLcode wait_or_timeout(struct Curl_multi *multi, struct events *ev)
           int act = poll2cselect(fds[i].revents); /* convert */
           infof(multi->easyp,
                 "call curl_multi_socket_action(socket "
-                "%" CURL_FORMAT_SOCKET_T ")", fds[i].fd);
+                "%" CURL_FORMAT_SOCKET_T ")", (curl_socket_t)fds[i].fd);
           mcode = curl_multi_socket_action(multi, fds[i].fd, act,
                                            &ev->running_handles);
         }
diff --git a/lib/if2ip.c b/lib/if2ip.c
index 42e14500bc..55afd553d6 100644
--- a/lib/if2ip.c
+++ b/lib/if2ip.c
@@ -216,7 +216,15 @@ if2ip_result_t Curl_if2ip(int af,
   memcpy(req.ifr_name, interf, len + 1);
   req.ifr_addr.sa_family = AF_INET;
 
+#if defined(__GNUC__) && defined(_AIX)
+/* Suppress warning inside system headers */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wshift-sign-overflow"
+#endif
   if(ioctl(dummy, SIOCGIFADDR, &req) < 0) {
+#if defined(__GNUC__) && defined(_AIX)
+#pragma GCC diagnostic pop
+#endif
     sclose(dummy);
     /* With SIOCGIFADDR, we cannot tell the difference between an interface
        that does not exist and an interface that has no address of the
diff --git a/lib/memdebug.h b/lib/memdebug.h
index fd5cc2c94d..cabadbcc89 100644
--- a/lib/memdebug.h
+++ b/lib/memdebug.h
@@ -34,9 +34,9 @@
 #include "functypes.h"
 
 #if defined(__GNUC__) && __GNUC__ >= 3
-#  define ALLOC_FUNC __attribute__((malloc))
-#  define ALLOC_SIZE(s) __attribute__((alloc_size(s)))
-#  define ALLOC_SIZE2(n, s) __attribute__((alloc_size(n, s)))
+#  define ALLOC_FUNC __attribute__((__malloc__))
+#  define ALLOC_SIZE(s) __attribute__((__alloc_size__(s)))
+#  define ALLOC_SIZE2(n, s) __attribute__((__alloc_size__(n, s)))
 #elif defined(_MSC_VER)
 #  define ALLOC_FUNC __declspec(restrict)
 #  define ALLOC_SIZE(s)
@@ -114,11 +114,17 @@ CURL_EXTERN int curl_dbg_fclose(FILE *file, int line, const char *source);
 /* Set this symbol on the command-line, recompile all lib-sources */
 #undef strdup
 #define strdup(ptr) curl_dbg_strdup(ptr, __LINE__, __FILE__)
+#undef malloc
 #define malloc(size) curl_dbg_malloc(size, __LINE__, __FILE__)
+#undef calloc
 #define calloc(nbelem,size) curl_dbg_calloc(nbelem, size, __LINE__, __FILE__)
+#undef realloc
 #define realloc(ptr,size) curl_dbg_realloc(ptr, size, __LINE__, __FILE__)
+#undef free
 #define free(ptr) curl_dbg_free(ptr, __LINE__, __FILE__)
+#undef send
 #define send(a,b,c,d) curl_dbg_send(a,b,c,d, __LINE__, __FILE__)
+#undef recv
 #define recv(a,b,c,d) curl_dbg_recv(a,b,c,d, __LINE__, __FILE__)
 
 #ifdef _WIN32