diff --git a/packages/vms/config-vms.h b/packages/vms/config-vms.h
index 45ee1b18de883896fb779f70ea8d1db88d0a3116..275f0f12e071a3c760ffff9c09c4b51961bf538e 100644
--- a/packages/vms/config-vms.h
+++ b/packages/vms/config-vms.h
@@ -96,6 +96,9 @@
 /* Define if you have the strstr function.  */
 #define  HAVE_STRSTR 1
 
+/* Define if you have the ftruncate function. */
+#define HAVE_FTRUNCATE 1
+
 /* Define if you have the uname function.  */
 #define HAVE_UNAME 1
 
diff --git a/src/Makefile.netware b/src/Makefile.netware
index d3d14fdfcd4d853e541bb743403e68a41e5040a3..c5f73c70455461f66e239a005957e85869f78874 100644
--- a/src/Makefile.netware
+++ b/src/Makefile.netware
@@ -280,6 +280,7 @@ config.h: Makefile.netware
 	@echo $(DL)#define HAVE_ERR_H 1$(DL) >> $@
 	@echo $(DL)#define HAVE_FCNTL_H 1$(DL) >> $@
 	@echo $(DL)#define HAVE_FIONBIO 1$(DL) >> $@
+	@echo $(DL)#define HAVE_FTRUNCATE 1$(DL) >> $@
 	@echo $(DL)#define HAVE_GETHOSTBYADDR 1$(DL) >> $@
 	@echo $(DL)#define HAVE_GETTIMEOFDAY 1$(DL) >> $@
 	@echo $(DL)#define HAVE_INET_ADDR 1$(DL) >> $@
diff --git a/src/config-amigaos.h b/src/config-amigaos.h
index 2d66e37e3a07fc79d13ae59d6fa9ad4cb4cb5066..0f904a30fb8bb890308367bc9a48f0587b0b4092 100644
--- a/src/config-amigaos.h
+++ b/src/config-amigaos.h
@@ -18,6 +18,7 @@
 #define HAVE_TIME_H             1
 #define TIME_WITH_SYS_TIME      1
 #define HAVE_TERMIOS_H          1
+#define HAVE_FTRUNCATE          1
 
 #define HAVE_PWD_H              1
 
diff --git a/src/config-mac.h b/src/config-mac.h
index 36505c94ccdd6f630e05b4722fcb7da6ac72ae33..e1806d5c6b5b04a65614620f0e8f8452f2b81447 100644
--- a/src/config-mac.h
+++ b/src/config-mac.h
@@ -8,6 +8,7 @@
 
 #define HAVE_SETVBUF            1
 #define HAVE_UTIME              1
+#define HAVE_FTRUNCATE          1
 
 #define main(x,y) curl_main(x,y)
 
diff --git a/src/config-riscos.h b/src/config-riscos.h
index 166021421ec5e5075b2300b67f937a8965537228..3213364793d795675ab5549b75f4ed7581342fa6 100644
--- a/src/config-riscos.h
+++ b/src/config-riscos.h
@@ -89,6 +89,9 @@
 /* Define if you have the <fcntl.h> header file. */
 #define HAVE_FCNTL_H
 
+/* Define if you have the `ftruncate' function. */
+#define HAVE_FTRUNCATE
+
 /* Define if getaddrinfo exists and works */
 #define HAVE_GETADDRINFO
 
diff --git a/src/config-vms.h b/src/config-vms.h
index 79f1ba7b76c48caf56544a87eec18d75f1321716..3df6535d5826b7d4b5b2b458da83fd26863af63c 100644
--- a/src/config-vms.h
+++ b/src/config-vms.h
@@ -11,6 +11,9 @@
 /* Define if you have the <io.h> header file.  */
 #undef HAVE_IO_H
 
+/* Define if you have ftruncate()  */
+#define HAVE_FTRUNCATE 1
+
 /* Define if you have strdup() */
 #define HAVE_STRDUP 1
 
diff --git a/src/config-win32.h b/src/config-win32.h
index a7c0d16829fe4e31a2353aa5c9edc57b8d5e919f..c07c349e5dd6feed5d17dbbb6d522fc7cffcbc4e 100644
--- a/src/config-win32.h
+++ b/src/config-win32.h
@@ -14,6 +14,9 @@
 /* Define if you have the <limits.h> header file */
 #define HAVE_LIMITS_H 1
 
+/* Define if you have the ftruncate function. */
+#define HAVE_FTRUNCATE 1
+
 /* Define if you have the strdup function.  */
 #define HAVE_STRDUP 1
 
diff --git a/src/main.c b/src/main.c
index b37d1dae010aab62bd4b60d668863cde01b65e1b..43e9c4939a1ed7664fe6485521d5d9ac2e5be22b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3771,10 +3771,12 @@ operate(struct Configurable *config, int argc, char *argv[])
                           " bytes\n", outs.bytes);
                 fflush(outs.stream);
                 /* truncate file at the position where we started appending */
+#ifdef HAVE_FTRUNCATE
                 ftruncate( fileno(outs.stream), outs.init);
+#endif
                 /* now seek to the end of the file, the position where we
                    just truncated the file */
-                fseek(outs.stream, 0, SEEK_END);
+                fseek(outs.stream, outs.init, SEEK_SET);
                 outs.bytes = 0; /* clear for next round */
               }
               continue;