diff --git a/bindings/java/src/jni/javasigar.c b/bindings/java/src/jni/javasigar.c
index 7c767199..e1cc1267 100644
--- a/bindings/java/src/jni/javasigar.c
+++ b/bindings/java/src/jni/javasigar.c
@@ -1323,7 +1323,7 @@ JNIEXPORT jlongArray SIGAR_JNI(ptql_SigarProcessQuery_find)
 JNIEXPORT jboolean SIGAR_JNI(util_Getline_isatty)
 (JNIEnv *env, jclass cls)
 {
-    return isatty(fileno(stdin)) ? JNI_TRUE : JNI_FALSE;
+    return sigar_isatty(sigar_fileno(stdin)) ? JNI_TRUE : JNI_FALSE;
 }
 
 JNIEXPORT jstring SIGAR_JNI(util_Getline_getline)
diff --git a/bindings/java/src/jni/win32/registrykey.cpp b/bindings/java/src/jni/win32/registrykey.cpp
index 7c179bbb..9878ab54 100644
--- a/bindings/java/src/jni/win32/registrykey.cpp
+++ b/bindings/java/src/jni/win32/registrykey.cpp
@@ -115,7 +115,7 @@ JNIEXPORT jlong SIGAR_JNI(win32_RegistryKey_RegOpenKey)
 
     /* required under IBM/WebSphere 4.0 for certain keys */
     if (lpSubkey[len] != '\0') {
-        copy = wcsdup(lpSubkey);
+        copy = _wcsdup(lpSubkey);
         copy[len] = '\0';
     }
     else {
@@ -143,7 +143,7 @@ JNIEXPORT jint SIGAR_JNI(win32_RegistryKey_RegQueryIntValue)
     LONG    lErr;
     /* required under IBM/WebSphere 4.0 for certain keys */
     if (lpValueName[len] != '\0') {
-        copy = wcsdup(lpValueName);
+        copy = _wcsdup(lpValueName);
         copy[len] = '\0';
     }
     else {
@@ -206,7 +206,7 @@ JNIEXPORT jstring SIGAR_JNI(win32_RegistryKey_RegQueryStringValue)
     LONG    lErr;
     /* required under IBM/WebSphere 4.0 for certain keys */
     if (lpValueName[len] != '\0') {
-        copy = wcsdup(lpValueName);
+        copy = _wcsdup(lpValueName);
         copy[len] = '\0';
     }
     else {
diff --git a/include/sigar_private.h b/include/sigar_private.h
index ae1422c3..7b27e148 100644
--- a/include/sigar_private.h
+++ b/include/sigar_private.h
@@ -86,8 +86,11 @@
 #define sigar_strdup(s) \
     dmalloc_strdup(__FILE__, __LINE__, s, 0);
 #else
-#define sigar_strdup(s) \
-    strdup(s)
+#  ifdef WIN32
+#    define sigar_strdup(s) _strdup(s)
+#  else
+#    define sigar_strdup(s) strdup(s)
+#  endif
 #endif
 
 #define SIGAR_ZERO(s) \
diff --git a/include/sigar_util.h b/include/sigar_util.h
index 2a5f7136..42cadbfb 100644
--- a/include/sigar_util.h
+++ b/include/sigar_util.h
@@ -44,6 +44,16 @@
 #define sigar_isupper(c) \
     (isupper(((unsigned char)(c))))
 
+#ifdef WIN32
+#define sigar_fileno _fileno
+#define sigar_isatty _isatty
+#define sigar_write  _write
+#else
+#define sigar_fileno fileno
+#define sigar_isatty isatty
+#define sigar_write  write
+#endif
+
 #ifndef PROC_FS_ROOT
 #define PROC_FS_ROOT "/proc/"
 #endif
diff --git a/src/os/win32/peb.c b/src/os/win32/peb.c
index 61e8b39e..76ef1591 100644
--- a/src/os/win32/peb.c
+++ b/src/os/win32/peb.c
@@ -131,7 +131,7 @@ int sigar_parse_proc_args(sigar_t *sigar, WCHAR *buf,
     for (i=0; i<num; i++) {
         SIGAR_W2A(args[i], arg, SIGAR_CMDLINE_MAX);
         SIGAR_PROC_ARGS_GROW(procargs);
-        procargs->data[procargs->number++] = strdup(arg);
+        procargs->data[procargs->number++] = sigar_strdup(arg);
     }
 
     GlobalFree(args);
diff --git a/src/os/win32/win32_sigar.c b/src/os/win32/win32_sigar.c
index 80d26b0f..5c17d366 100644
--- a/src/os/win32/win32_sigar.c
+++ b/src/os/win32/win32_sigar.c
@@ -2410,7 +2410,7 @@ sigar_net_interface_list_get(sigar_t *sigar,
         }
 
         if (iflist) {
-            iflist->data[iflist->number++] = strdup(name);
+            iflist->data[iflist->number++] = sigar_strdup(name);
         }
 
         key = netif_hash(name);
diff --git a/src/sigar_getline.c b/src/sigar_getline.c
index c9fdc848..0a8946bc 100644
--- a/src/sigar_getline.c
+++ b/src/sigar_getline.c
@@ -660,13 +660,13 @@ gl_putc(int c)
        CharToOemBuff((char const *)&c,&ch,1);
 #endif
 
-       write(1, &ch, 1);
+       sigar_write(1, &ch, 1);
     }
 #if defined(unix) || defined(MSDOS) || defined(WIN32) || defined(R__MWERKS)
 #ifdef TIOCSETP         /* BSD in RAW mode, map NL to NL,CR */
     if (ch == '\n') {
         ch = '\r';
-        write(1, &ch, 1);
+        sigar_write(1, &ch, 1);
     }
 #endif
 #endif
@@ -684,11 +684,11 @@ gl_puts(char *buf)
     {
      char *OemBuf = (char *)malloc(2*len);
      CharToOemBuff(buf,OemBuf,len);
-     write(1, OemBuf, len);
+     sigar_write(1, OemBuf, len);
      free(OemBuf);
     }
 #else
-    write(1, buf, len);
+    sigar_write(1, buf, len);
 #endif
 }
 
@@ -702,11 +702,11 @@ gl_error(char *buf)
     {
       char *OemBuf = (char *)malloc(2*len);
       CharToOemBuff(buf,OemBuf,len);
-      write(2, OemBuf, len);
+      sigar_write(2, OemBuf, len);
       free(OemBuf);
     }
 #else
-    write(2, buf, len);
+    sigar_write(2, buf, len);
 #endif
     exit(1);
 }
@@ -718,7 +718,7 @@ gl_init()
     if (gl_init_done < 0) {             /* -1 only on startup */
         hist_init();
     }
-    if (isatty(0) == 0 || isatty(1) == 0)
+    if (sigar_isatty(0) == 0 || sigar_isatty(1) == 0)
         gl_notty = 1;
     gl_char_init();
     gl_init_done = 1;
@@ -756,7 +756,7 @@ SIGAR_DECLARE(void)
 sigar_getline_windowchanged()
 {
 #ifdef TIOCGWINSZ
-   if (isatty(0)) {
+   if (sigar_isatty(0)) {
       static char lenv[32], cenv[32];
       struct winsize wins;
       ioctl(0, TIOCGWINSZ, &wins);
diff --git a/src/sigar_ptql.c b/src/sigar_ptql.c
index 409a8a56..2ff3ff23 100644
--- a/src/sigar_ptql.c
+++ b/src/sigar_ptql.c
@@ -531,7 +531,7 @@ static int ptql_branch_list_destroy(ptql_branch_list_t *branches)
 static int ptql_branch_init_any(ptql_parse_branch_t *parsed,
                                 ptql_branch_t *branch)
 {
-    branch->data.str = strdup(parsed->attr);
+    branch->data.str = sigar_strdup(parsed->attr);
     branch->data_size = strlen(parsed->attr);
     return SIGAR_OK;
 }
@@ -654,14 +654,14 @@ static int ptql_branch_init_pid(ptql_parse_branch_t *parsed,
     }
     else if (strEQ(parsed->attr, "PidFile")) {
         branch->flags = PTQL_PID_FILE;
-        branch->data.str = strdup(parsed->value);
+        branch->data.str = sigar_strdup(parsed->value);
         branch->data_size = strlen(parsed->value);
         return SIGAR_OK;
     }
     else if (strEQ(parsed->attr, "Service")) {
         branch->flags = PTQL_PID_SERVICE;
 #ifdef WIN32
-        branch->data.str = strdup(parsed->value);
+        branch->data.str = sigar_strdup(parsed->value);
         branch->data_size = strlen(parsed->value);
 #endif
         return SIGAR_OK;
@@ -1148,7 +1148,7 @@ static int ptql_branch_add(ptql_parse_branch_t *parsed,
         }
         else {
             if ((ptr = getenv(parsed->value+1))) {
-                branch->value.str = strdup(ptr);
+                branch->value.str = sigar_strdup(ptr);
             }
             else {
                 branch->value.str = NULL;
@@ -1212,7 +1212,7 @@ static int ptql_branch_add(ptql_parse_branch_t *parsed,
       case PTQL_VALUE_TYPE_ANY:
         branch->match.str = ptql_op_str[branch->op_name];
         if (!is_set) {
-            branch->value.str = strdup(parsed->value);
+            branch->value.str = sigar_strdup(parsed->value);
         }
         break;
     }
@@ -1233,14 +1233,14 @@ static int ptql_branch_compare(const void *b1, const void *b2)
 SIGAR_DECLARE(int) sigar_ptql_query_create(sigar_ptql_query_t **queryp,
                                            char *ptql)
 {
-    char *ptr, *ptql_copy = strdup(ptql);
+    char *ptr, *ptql_copy = sigar_strdup(ptql);
     int status = SIGAR_OK;
     int has_ref = 0;
     sigar_ptql_query_t *query =
         *queryp = malloc(sizeof(*query));
 
 #ifdef PTQL_DEBUG
-    query->ptql = strdup(ptql);
+    query->ptql = sigar_strdup(ptql);
 #endif
 
     ptql = ptql_copy;