diff --git a/contrib/basic_archive/basic_archive.c b/contrib/basic_archive/basic_archive.c
index 8c7e9be624f..914a0b56d16 100644
--- a/contrib/basic_archive/basic_archive.c
+++ b/contrib/basic_archive/basic_archive.c
@@ -100,7 +100,7 @@ check_archive_directory(char **newval, void **extra, GucSource source)
 	 * Our check_configured callback also checks for this and prevents
 	 * archiving from proceeding if it is still empty.
 	 */
-	if (*newval == NULL || *newval[0] == '\0')
+	if (*newval == NULL || (*newval)[0] == '\0')
 		return true;
 
 	/*
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 80b78f25267..314ef85fdb4 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -2627,7 +2627,7 @@ check_backtrace_functions(char **newval, void **extra, GucSource source)
 		return false;
 	}
 
-	if (*newval[0] == '\0')
+	if ((*newval)[0] == '\0')
 	{
 		*extra = NULL;
 		return true;