diff --git a/rtl/inc/matrix.pp b/rtl/inc/matrix.pp
index b7dd6c5156..69b9cd1448 100644
--- a/rtl/inc/matrix.pp
+++ b/rtl/inc/matrix.pp
@@ -30,6 +30,7 @@ unit matrix;
 interface
 
 {*****************************************************************************}
+{$mode fpc}
 
 {$ifndef FPUNONE}
 {$MACRO on}