diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index ccf63e9309..d948369f3e 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4801,6 +4801,14 @@ SubPostmasterMain(int argc, char *argv[])
 	/* Read in remaining GUC variables */
 	read_nondefault_variables();
 
+	/*
+	 * Check that the data directory looks valid, which will also check the
+	 * privileges on the data directory and update our umask and file/group
+	 * variables for creating files later.  Note: this should really be done
+	 * before we create any files or directories.
+	 */
+	checkDataDir();
+
 	/*
 	 * (re-)read control file, as it contains config. The postmaster will
 	 * already have read this, but this process doesn't know about that.
diff --git a/src/common/file_perm.c b/src/common/file_perm.c
index d640d6a1fd..f2c8f84609 100644
--- a/src/common/file_perm.c
+++ b/src/common/file_perm.c
@@ -78,9 +78,14 @@ GetDataDirectoryCreatePerm(const char *dataDir)
 
 	/* Set permissions */
 	SetDataDirectoryCreatePerm(statBuf.st_mode);
-
 	return true;
-#endif							/* !defined(WIN32) && !defined(__CYGWIN__) */
+#else							/* !defined(WIN32) && !defined(__CYGWIN__) */
+	/*
+	 * On Windows, we don't have anything to do here since they don't have
+	 * Unix-y permissions.
+	 */
+	return true;
+#endif
 }