diff --git a/configure.in b/configure.in
index e762777f..98e151ca 100644
--- a/configure.in
+++ b/configure.in
@@ -111,6 +111,9 @@ AC_CHECK_HEADERS(strings.h)
 dnl Look for <stdbool.h>
 AC_HEADER_STDBOOL
 
+dnl Look for <io.h>
+AC_CHECK_HEADERS(io.h)
+
 dnl Look for <unistd.h>
 AC_CHECK_HEADERS(unistd.h)
 
@@ -135,6 +138,11 @@ AC_CHECK_FUNCS(canonicalize_file_name)
 AC_CHECK_FUNCS(_fullpath)
 AC_CHECK_FUNCS(pathconf)
 
+AC_TYPE_OFF_T
+AC_FUNC_FSEEKO
+AC_CHECK_FUNCS([ftruncate _chsize _chsize_s])
+AC_CHECK_FUNCS([fileno])
+
 PA_HAVE_FUNC(__builtin_ctz, (0U))
 PA_HAVE_FUNC(__builtin_ctzl, (0UL))
 PA_HAVE_FUNC(__builtin_ctzll, (0ULL))
diff --git a/nasmlib.c b/nasmlib.c
index 49f1e470..eb0217d1 100644
--- a/nasmlib.c
+++ b/nasmlib.c
@@ -165,7 +165,7 @@ no_return nasm_assert_failed(const char *file, int line, const char *msg)
 void nasm_write(const void *ptr, size_t size, FILE *f)
 {
     size_t n = fwrite(ptr, 1, size, f);
-    if (n != size)
+    if (n != size || ferror(f) || feof(f))
         nasm_error(ERR_FATAL, "unable to write output: %s", strerror(errno));
 }
 
@@ -459,10 +459,37 @@ void fwriteaddr(uint64_t data, int size, FILE * fp)
 
 #endif
 
+#ifndef HAVE_FSEEKO
+# define fseeko fseek
+# define ftello ftell
+#endif
+
+#ifdef HAVE_FILENO		/* Useless without fileno() */
+# ifdef HAVE__CHSIZE_S
+#  define nasm_ftruncate(fd,size) _chsize_s(fd,size)
+# elif defined(HAVE__CHSIZE)
+#  define nasm_ftruncate(fd,size) _chsize(fd,size)
+# elif defined(HAVE_FTRUNCATE)
+#  define nasm_ftruncate(fd,size) ftruncate(fd,size)
+# endif
+#endif
+
 void fwritezero(size_t bytes, FILE *fp)
 {
     size_t blksize;
 
+#ifdef nasm_ftruncate
+    if (bytes >= BUFSIZ && !ferror(fp) && !feof(fp)) {
+	off_t pos = ftello(fp);
+	if (pos >= 0) {
+	    if (!fflush(fp) &&
+		!nasm_ftruncate(fileno(fp), pos + bytes) &&
+		!fseeko(fp, pos+bytes, SEEK_SET))
+		    return;
+	}
+    }
+#endif
+
     while (bytes) {
 	blksize = (bytes < ZERO_BUF_SIZE) ? bytes : ZERO_BUF_SIZE;
 
diff --git a/nasmlib.h b/nasmlib.h
index 96c488a4..534324db 100644
--- a/nasmlib.h
+++ b/nasmlib.h
@@ -44,7 +44,13 @@
 #include <stdio.h>
 #include <string.h>
 #ifdef HAVE_STRINGS_H
-#include <strings.h>
+# include <strings.h>
+#endif
+#ifdef HAVE_IO_H
+# include <io.h>
+#endif
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
 #endif
 
 /*