diff --git a/src/fileio.c b/src/fileio.c
index 9224777..362d82e 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -445,7 +445,7 @@
 	    return FAIL;
 	}
 #endif
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 	/*
 	 * MS-Windows allows opening a device, but we will probably get stuck
 	 * trying to read it.
@@ -526,7 +526,7 @@
     file_readonly = FALSE;
     if (read_stdin)
     {
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 	/* Force binary I/O on stdin to avoid CR-LF -> LF conversion. */
 	setmode(0, O_BINARY);
 #endif
@@ -3553,7 +3553,7 @@
     }
     if (c == NODE_WRITABLE)
     {
-# if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+# if defined(MSDOS) || defined(MSWIN)
 	/* MS-Windows allows opening a device, but we will probably get stuck
 	 * trying to write to it.  */
 	if (!p_odev)
@@ -6055,7 +6055,7 @@
     if (fnamencmp(dir_name, full_path, len) == 0)
     {
 	p = full_path + len;
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
 	/*
 	 * MSDOS: when a file is in the root directory, dir_name will end in a
 	 * slash, since C: by itself does not define a specific dir. In this
@@ -6072,7 +6072,7 @@
 #endif
 	}
     }
-#if defined(MSDOS) || defined(MSWIN) || defined(OS2)
+#if defined(MSDOS) || defined(MSWIN)
     /*
      * When using a file in the current drive, remove the drive name:
      * "A:\dir\file" -> "\dir\file".  This helps when moving a session file on
@@ -6330,7 +6330,7 @@
 	else if ((int)STRLEN(e) + extlen > 4)
 	    s = e + 4 - extlen;
     }
-#if defined(OS2) || defined(USE_LONG_FNAME) || defined(WIN3264)
+#if defined(USE_LONG_FNAME) || defined(WIN3264)
     /*
      * If there is no file name, and the extension starts with '.', put a
      * '_' before the dot, because just ".ext" may be invalid if it's on a