diff --git a/goalc/compiler/Compiler.h b/goalc/compiler/Compiler.h
index bc661f0f71..d95faf7e93 100644
--- a/goalc/compiler/Compiler.h
+++ b/goalc/compiler/Compiler.h
@@ -557,6 +557,7 @@ class Compiler {
   Val* compile_none(const goos::Object& form, const goos::Object& rest, Env* env);
   Val* compile_defenum(const goos::Object& form, const goos::Object& rest, Env* env);
   Val* compile_size_of(const goos::Object& form, const goos::Object& rest, Env* env);
+  Val* compile_psize_of(const goos::Object& form, const goos::Object& rest, Env* env);
 };
 
 extern const std::unordered_map<
diff --git a/goalc/compiler/compilation/Atoms.cpp b/goalc/compiler/compilation/Atoms.cpp
index 95393fc1d8..f1b03485ea 100644
--- a/goalc/compiler/compilation/Atoms.cpp
+++ b/goalc/compiler/compilation/Atoms.cpp
@@ -174,6 +174,7 @@ const std::unordered_map<
         {"declare-type", &Compiler::compile_declare_type},
         {"none", &Compiler::compile_none},
         {"size-of", &Compiler::compile_size_of},
+        {"psize-of", &Compiler::compile_psize_of},
 
         // LAMBDA
         {"lambda", &Compiler::compile_lambda},
diff --git a/goalc/compiler/compilation/Type.cpp b/goalc/compiler/compilation/Type.cpp
index b3000dd2b2..f0e63ebc3b 100644
--- a/goalc/compiler/compilation/Type.cpp
+++ b/goalc/compiler/compilation/Type.cpp
@@ -1260,3 +1260,7 @@ int Compiler::get_size_for_size_of(const goos::Object& form, const goos::Object&
 Val* Compiler::compile_size_of(const goos::Object& form, const goos::Object& rest, Env* env) {
   return compile_integer(get_size_for_size_of(form, rest), env);
 }
+
+Val* Compiler::compile_psize_of(const goos::Object& form, const goos::Object& rest, Env* env) {
+  return compile_integer((get_size_for_size_of(form, rest) + 0xf) & ~0xf, env);
+}