Index: contrib/bmake/parse.c
===================================================================
--- contrib/bmake/parse.c
+++ contrib/bmake/parse.c
@@ -309,6 +309,9 @@
     { ".WAIT",		SP_WAIT,	OP_NONE },
 };
 
+#ifdef POSIX
+static int dot_POSIX_valid = 0;
+#endif
 
 static IncludedFile *
 GetInclude(size_t i)
@@ -1267,6 +1270,8 @@
 		break;
 #ifdef POSIX
 	case SP_POSIX:
+		if (!dot_POSIX_valid)
+			break;
 		Global_Set("%POSIX", "1003.2");
 		{
 			static bool first_posix = true;
@@ -2898,6 +2903,9 @@
 	char *line;
 	Buffer buf;
 
+#ifdef POSIX
+	dot_POSIX_valid = 1;
+#endif
 	buf = loadfile(name, fd != -1 ? fd : STDIN_FILENO);
 	if (fd != -1)
 		(void)close(fd);
@@ -2911,6 +2919,9 @@
 			DEBUG2(PARSE, "Parsing line %u: %s\n",
 			    CurFile()->lineno, line);
 			ParseLine(line);
+#ifdef POSIX
+			dot_POSIX_valid = 0;
+#endif
 		}
 		/* Reached EOF, but it may be just EOF of an include file. */
 	} while (ParseEOF());