diff --git a/basis/alien/arrays/arrays.factor b/basis/alien/arrays/arrays.factor
index 94472e8261..727492edb1 100644
--- a/basis/alien/arrays/arrays.factor
+++ b/basis/alien/arrays/arrays.factor
@@ -8,6 +8,8 @@ UNION: value-type array struct-type ;
 
 M: array c-type ;
 
+M: array c-type-class drop object ;
+
 M: array heap-size unclip heap-size [ * ] reduce ;
 
 M: array c-type-align first c-type-align ;
diff --git a/basis/alien/strings/strings.factor b/basis/alien/strings/strings.factor
index 70bbe773ee..b0faadb7fc 100644
--- a/basis/alien/strings/strings.factor
+++ b/basis/alien/strings/strings.factor
@@ -40,6 +40,9 @@ PREDICATE: string-type < pair
 
 M: string-type c-type ;
 
+M: string-type c-type-class
+    drop object ;
+
 M: string-type heap-size
     drop "void*" heap-size ;
 
diff --git a/basis/alien/structs/structs.factor b/basis/alien/structs/structs.factor
index adb25aa977..1131b1eecd 100644
--- a/basis/alien/structs/structs.factor
+++ b/basis/alien/structs/structs.factor
@@ -9,6 +9,8 @@ TUPLE: struct-type size align fields ;
 
 M: struct-type heap-size size>> ;
 
+M: struct-type c-type-class drop object ;
+
 M: struct-type c-type-align align>> ;
 
 M: struct-type c-type-stack-align? drop f ;