diff --git a/src/memory.rs b/src/memory.rs
index cff4cc35c84..72dd0d9b1e9 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -201,6 +201,7 @@ impl Memory {
     }
 
     pub fn write_primval(&mut self, ptr: Pointer, val: PrimVal) -> EvalResult<()> {
+        let pointer_size = self.pointer_size;
         match val {
             PrimVal::Bool(b) => self.write_bool(ptr, b),
             PrimVal::I8(n)   => self.write_int(ptr, n as i64, 1),
@@ -210,7 +211,8 @@ impl Memory {
             PrimVal::U8(n)   => self.write_uint(ptr, n as u64, 1),
             PrimVal::U16(n)  => self.write_uint(ptr, n as u64, 2),
             PrimVal::U32(n)  => self.write_uint(ptr, n as u64, 4),
-            PrimVal::U64(n) | PrimVal::IntegerPtr(n) => self.write_uint(ptr, n as u64, 8),
+            PrimVal::U64(n)  => self.write_uint(ptr, n as u64, 8),
+            PrimVal::IntegerPtr(n) => self.write_uint(ptr, n as u64, pointer_size),
             PrimVal::AbstractPtr(_p) => unimplemented!(),
         }
     }