diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index c03ec946..fbc90fe4 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -72,14 +72,12 @@ static int BinTree__cmp_cstr(void* lhs, void* rhs) {
     return strcmp(l, r);
 }
 
-static int BinTree__cmp_voidp(void* lhs, void* rhs) {
-    return lhs < rhs ? -1 : (lhs > rhs ? 1 : 0);
-}
+static int BinTree__cmp_voidp(void* lhs, void* rhs) { return lhs < rhs ? -1 : (lhs > rhs ? 1 : 0); }
 
 void VM__ctor(VM* self) {
     self->top_frame = NULL;
 
-    static const BinTreeConfig modules_config = {
+    const static BinTreeConfig modules_config = {
         .f_cmp = BinTree__cmp_cstr,
         .need_free_key = true,
     };
@@ -114,7 +112,7 @@ void VM__ctor(VM* self) {
     ManagedHeap__ctor(&self->heap);
     ValueStack__ctor(&self->stack);
 
-    static const BinTreeConfig cached_names_config = {
+    const static BinTreeConfig cached_names_config = {
         .f_cmp = BinTree__cmp_voidp,
         .need_free_key = false,
     };
@@ -417,6 +415,7 @@ py_Type pk_newtype(const char* name,
 }
 
 py_Type py_newtype(const char* name, py_Type base, const py_GlobalRef module, void (*dtor)(void*)) {
+    if(strlen(name) == 0) c11__abort("type name cannot be empty");
     py_Type type = pk_newtype(name, base, module, dtor, false, false);
     if(module) py_setdict(module, py_name(name), py_tpobject(type));
     return type;
diff --git a/src/public/modules.c b/src/public/modules.c
index 43c25163..e060dd7e 100644
--- a/src/public/modules.c
+++ b/src/public/modules.c
@@ -24,7 +24,10 @@ void py_setglobal(py_Name name, py_Ref val) { py_setdict(&pk_current_vm->main, n
 
 py_Ref py_newmodule(const char* path) {
     ManagedHeap* heap = &pk_current_vm->heap;
-    if(strlen(path) > PK_MAX_MODULE_PATH_LEN) c11__abort("module path too long: %s", path);
+
+    int path_len = strlen(path);
+    if(path_len > PK_MAX_MODULE_PATH_LEN) c11__abort("module path too long: %s", path);
+    if(path_len == 0) c11__abort("module path cannot be empty");
 
     py_Ref r0 = py_pushtmp();
     py_Ref r1 = py_pushtmp();
@@ -35,7 +38,7 @@ py_Ref py_newmodule(const char* path) {
         ._obj = ManagedHeap__new(heap, tp_module, -1, 0),
     };
 
-    int last_dot = c11_sv__rindex((c11_sv){path, strlen(path)}, '.');
+    int last_dot = c11_sv__rindex((c11_sv){path, path_len}, '.');
     if(last_dot == -1) {
         py_newstr(r1, path);
         py_setdict(r0, __name__, r1);