diff --git a/src/pkg/runtime/darwin/386/defs.h b/src/pkg/runtime/darwin/386/defs.h
index 69ccc35f7d..371f650a87 100644
--- a/src/pkg/runtime/darwin/386/defs.h
+++ b/src/pkg/runtime/darwin/386/defs.h
@@ -1,4 +1,4 @@
-// godefs defs.c
+// godefs -f -m32 defs.c
 
 // MACHINE GENERATED - DO NOT EDIT.
 
diff --git a/src/pkg/runtime/darwin/defs.c b/src/pkg/runtime/darwin/defs.c
index 95edf7bb10..8735e78572 100644
--- a/src/pkg/runtime/darwin/defs.c
+++ b/src/pkg/runtime/darwin/defs.c
@@ -6,7 +6,7 @@
  * Input to godefs.
  *
 	godefs -f -m64 defs.c >amd64/defs.h
-	godefs defs.c >386/defs.h
+	godefs -f -m32 defs.c >386/defs.h
  */
 
 #define __DARWIN_UNIX03 0
diff --git a/src/pkg/runtime/freebsd/386/defs.h b/src/pkg/runtime/freebsd/386/defs.h
index 69b8661eb0..76c55721f6 100644
--- a/src/pkg/runtime/freebsd/386/defs.h
+++ b/src/pkg/runtime/freebsd/386/defs.h
@@ -1,4 +1,4 @@
-// godefs defs.c
+// godefs -f -m32 defs.c
 
 // MACHINE GENERATED - DO NOT EDIT.
 
diff --git a/src/pkg/runtime/freebsd/defs.c b/src/pkg/runtime/freebsd/defs.c
index 0c75e75c4c..36e69093e4 100644
--- a/src/pkg/runtime/freebsd/defs.c
+++ b/src/pkg/runtime/freebsd/defs.c
@@ -6,7 +6,7 @@
  * Input to godefs.
  *
 	godefs -f -m64 defs.c >amd64/defs.h
-	godefs defs.c >386/defs.h
+	godefs -f -m32 defs.c >386/defs.h
  */
 
 #include <sys/types.h>