diff --git a/spa/plugins/filter-graph/builtin_plugin.c b/spa/plugins/filter-graph/builtin_plugin.c
index 467b62a17..9d293acdb 100644
--- a/spa/plugins/filter-graph/builtin_plugin.c
+++ b/spa/plugins/filter-graph/builtin_plugin.c
@@ -2802,6 +2802,10 @@ static struct spa_fga_port zeroramp_ports[] = {
 	},
 };
 
+#ifndef M_PIf
+# define M_PIf	3.14159265358979323846f /* pi */
+#endif
+
 static void zeroramp_run(void * Instance, unsigned long SampleCount)
 {
 	struct builtin *impl = Instance;