diff --git a/lib/hostares.c b/lib/hostares.c
index baaa4b0fb..6ea6e51d5 100644
--- a/lib/hostares.c
+++ b/lib/hostares.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H  /* Win32 */
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
diff --git a/lib/hostasyn.c b/lib/hostasyn.c
index d1b7cdd18..f9e9edbef 100644
--- a/lib/hostasyn.c
+++ b/lib/hostasyn.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H  /* Win32 */
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
diff --git a/lib/hostip.c b/lib/hostip.c
index 6cf652f87..407c6b2f8 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H  /* Win32 */
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
diff --git a/lib/hostip4.c b/lib/hostip4.c
index c7bdb6dc9..4e57d3e80 100644
--- a/lib/hostip4.c
+++ b/lib/hostip4.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H  /* Win32 */
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
diff --git a/lib/hostip6.c b/lib/hostip6.c
index ae36ad738..693b98e4c 100644
--- a/lib/hostip6.c
+++ b/lib/hostip6.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
@@ -143,10 +142,10 @@ int curl_dogetnameinfo(const struct sockaddr *sa, socklen_t salen,
                        char *serv, size_t servlen, int flags,
                        int line, const char *source)
 {
-  int res = (getnameinfo)(sa, salen, 
-                          host, hostlen, 
-                          serv, servlen, 
-                          flags); 
+  int res = (getnameinfo)(sa, salen,
+                          host, hostlen,
+                          serv, servlen,
+                          flags);
   if(0 == res) {
     /* success */
     if(logfile)
diff --git a/lib/hostsyn.c b/lib/hostsyn.c
index fac78f11f..30dc4963a 100644
--- a/lib/hostsyn.c
+++ b/lib/hostsyn.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,13 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
diff --git a/lib/hostthre.c b/lib/hostthre.c
index 32d212f14..504af41b6 100644
--- a/lib/hostthre.c
+++ b/lib/hostthre.c
@@ -26,9 +26,9 @@
 #include <string.h>
 #include <errno.h>
 
-#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
+#ifdef HAVE_MALLOC_H
 #include <malloc.h>
-#else
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -55,14 +55,12 @@
 #include <inet.h>
 #include <stdlib.h>
 #endif
-#endif
 
 #ifdef HAVE_SETJMP_H
 #include <setjmp.h>
 #endif
 
-#ifdef WIN32
-#include <stdlib.h>
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
 
@@ -301,7 +299,7 @@ static unsigned __stdcall gethostbyname_thread (void *arg)
   struct thread_sync_data tsd = { 0,0,0,NULL };
   if (!init_thread_sync_data(td, conn->async.hostname, &tsd)) {
     /* thread synchronization data initialization failed */
-    return -1;
+    return (unsigned)-1;
   }
 
   /* Sharing the same _iob[] element with our parent thread should
@@ -570,7 +568,7 @@ static bool init_resolve_thread (struct connectdata *conn,
   thread_and_event[1] = td->event_thread_started;
   if (WaitForMultipleObjects(sizeof(thread_and_event) /
                              sizeof(thread_and_event[0]),
-                             thread_and_event, FALSE,
+                             (const HANDLE*)thread_and_event, FALSE,
                              INFINITE) == WAIT_FAILED) {
     /* The resolver thread has been created,
      * most probably it works now - ignoring this "minor" error
diff --git a/lib/ldap.c b/lib/ldap.c
index 47b5fdefd..558d6f40f 100644
--- a/lib/ldap.c
+++ b/lib/ldap.c
@@ -36,10 +36,12 @@
 #ifdef HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
+#ifdef HAVE_MALLOC_H
+#include <malloc.h>
+#endif
 #include <errno.h>
 
 #if defined(WIN32)
-# include <malloc.h>
 # include <winldap.h>
 #endif