diff --git a/src/lib/conversion/rotation.cpp b/src/lib/conversion/rotation.cpp
index 00ce40dd01..ae3bd011a4 100644
--- a/src/lib/conversion/rotation.cpp
+++ b/src/lib/conversion/rotation.cpp
@@ -173,8 +173,10 @@ rotate_3f(enum Rotation rot, float &x, float &y, float &z)
 		}
 
 	case ROTATION_ROLL_90_YAW_90: {
-			tmp = z; z = y; y = -tmp;
-			tmp = x; x = -y; y = tmp;
+			tmp = x;
+			x = z;
+			z = y;
+			y = tmp;
 			return;
 		}