diff --git a/compiler/fpcdefs.inc b/compiler/fpcdefs.inc
index 7e70a26ad0..bb799c3878 100644
--- a/compiler/fpcdefs.inc
+++ b/compiler/fpcdefs.inc
@@ -106,3 +106,7 @@
 {$ENDIF MACOS}
 
 {$define SUPPORT_UNALIGNED}
+
+{$if not defined(cpui386) and defined(i386)}
+{$error Cross-compiling from non-i386 to i386 is not yet supported at this time }
+{$endif}