diff --git a/devel/tree-sitter-java/Portfile b/devel/tree-sitter-java/Portfile
index e203989f1da9b..edc4a13713def 100644
--- a/devel/tree-sitter-java/Portfile
+++ b/devel/tree-sitter-java/Portfile
@@ -20,3 +20,6 @@ checksums           rmd160  d7a7edd59da97821271638c864245dd27851ab2e \
                     size    212497
 
 worksrcdir          ${worksrcdir}/src
+
+# parser.c: error: ‘for’ loop initial declaration used outside C99 mode
+configure.cflags-append -std=c99