diff --git a/src/libs/mesa/glut/glutGet.cpp b/src/libs/mesa/glut/glutGet.cpp
index 3a653af722..9214e68376 100644
--- a/src/libs/mesa/glut/glutGet.cpp
+++ b/src/libs/mesa/glut/glutGet.cpp
@@ -224,6 +224,10 @@ int glutGetModifiers() {
 
 #ifdef __HAIKU__
 
+extern "C" {
+GLUTproc __glutGetProcAddress(const char* procName);
+}
+
 GLUTproc
 __glutGetProcAddress(const char* procName)
 {