diff --git a/basis/alien/c-types/c-types.factor b/basis/alien/c-types/c-types.factor
index 9cd57f61ab..6067c90f2d 100755
--- a/basis/alien/c-types/c-types.factor
+++ b/basis/alien/c-types/c-types.factor
@@ -409,10 +409,10 @@ CONSTANT: primitive-types
     "uchar" define-primitive-type
 
     <c-type>
-        [ alien-unsigned-4 zero? not ] >>getter
-        [ [ 1 0 ? ] 2dip set-alien-unsigned-4 ] >>setter
-        4 >>size
-        4 >>align
+        [ alien-unsigned-1 zero? not ] >>getter
+        [ [ 1 0 ? ] 2dip set-alien-unsigned-1 ] >>setter
+        1 >>size
+        1 >>align
         "box_boolean" >>boxer
         "to_boolean" >>unboxer
     "bool" define-primitive-type
diff --git a/basis/compiler/tests/alien.factor b/basis/compiler/tests/alien.factor
index 42ed90d64a..f7f24433d7 100755
--- a/basis/compiler/tests/alien.factor
+++ b/basis/compiler/tests/alien.factor
@@ -588,3 +588,16 @@ FUNCTION: complex-float ffi_test_47 ( complex-float x, complex-double y ) ;
     C{ 1.0 2.0 }
     C{ 1.5 1.0 } ffi_test_47
 ] unit-test
+
+! Reported by jedahu
+C-STRUCT: bool-field-test
+   { "char*" "name" }
+   { "bool"  "on" }
+   { "short" "parents" } ;
+
+FUNCTION: short ffi_test_48 ( bool-field-test x ) ;
+
+[ 123 ] [
+    "bool-field-test" <c-object> 123 over set-bool-field-test-parents
+    ffi_test_48
+] unit-test
\ No newline at end of file
diff --git a/vm/ffi_test.c b/vm/ffi_test.c
index 680b144140..d45ceb4514 100755
--- a/vm/ffi_test.c
+++ b/vm/ffi_test.c
@@ -319,3 +319,8 @@ _Complex float ffi_test_47(_Complex float x, _Complex double y)
 {
 	return x + 2 * y;
 }
+
+short ffi_test_48(struct bool_field_test x)
+{
+	return x.parents;
+}
diff --git a/vm/ffi_test.h b/vm/ffi_test.h
index 835f9e942f..af0c0b46a4 100755
--- a/vm/ffi_test.h
+++ b/vm/ffi_test.h
@@ -1,3 +1,5 @@
+#include <stdbool.h>
+
 #if defined(i386) || defined(__i386) || defined(__i386__) || defined(WIN32)
 	#define F_STDCALL __attribute__((stdcall))
 #else
@@ -102,3 +104,11 @@ F_EXPORT _Complex float ffi_test_45(int x);
 F_EXPORT _Complex double ffi_test_46(int x);
 
 F_EXPORT _Complex float ffi_test_47(_Complex float x, _Complex double y);
+
+struct bool_field_test {
+	char *name;
+	bool on;
+	short parents;
+};
+
+F_EXPORT short ffi_test_48(struct bool_field_test x);