diff --git a/java/libraries/opengl/src/processing/opengl/PGraphicsOpenGL.java b/java/libraries/opengl/src/processing/opengl/PGraphicsOpenGL.java
index fe27cb192..1ed6201a8 100644
--- a/java/libraries/opengl/src/processing/opengl/PGraphicsOpenGL.java
+++ b/java/libraries/opengl/src/processing/opengl/PGraphicsOpenGL.java
@@ -4946,7 +4946,7 @@ return width * (1 + ox) / 2.0f;
     glprojection[3] = 0.0f;
 
     glprojection[4] = 0.0f;
-    glprojection[5] = y;
+    glprojection[5] = -y; // The minus here inverts the Y axis in order to use Processing's convention
     glprojection[6] = 0.0f;
     glprojection[7] = 0.0f;