diff --git a/include/cyclone/runtime.h b/include/cyclone/runtime.h
index 21b204c5..119338e9 100644
--- a/include/cyclone/runtime.h
+++ b/include/cyclone/runtime.h
@@ -719,6 +719,7 @@ uint32_t Cyc_utf8_decode(uint32_t* state, uint32_t* codep, uint32_t byte);
 int Cyc_utf8_count_code_points(uint8_t* s);
 uint32_t Cyc_utf8_validate_stream(uint32_t *state, char *str, size_t len); 
 uint32_t Cyc_utf8_validate(char *str, size_t len);
+int uint32_num_bytes(uint32_t val);
 /**@}*/
 
 #endif                          /* CYCLONE_RUNTIME_H */
diff --git a/runtime.c b/runtime.c
index da3f255c..79badbf9 100644
--- a/runtime.c
+++ b/runtime.c
@@ -178,6 +178,7 @@ void pack_env_variables(void *data, object k)
     svar->hdr.grayed = 0;
     svar->tag = string_tag; 
     svar->len = eqpos - e;
+    svar->num_cp = svar->len; // TODO: proper UTF-8 support!
     svar->str = alloca(sizeof(char) * (svar->len));
     strncpy(svar->str, e, svar->len);
     (svar->str)[svar->len] = '\0';
@@ -189,6 +190,7 @@ void pack_env_variables(void *data, object k)
     sval->hdr.grayed = 0;
     sval->tag = string_tag; 
     sval->len = strlen(eqpos);
+    sval->num_cp = sval->len; // TODO: proper UTF-8 support!
     sval->str = eqpos;
     set_pair(tmp, svar, sval);
     set_pair(p, tmp, NULL);
@@ -6553,4 +6555,12 @@ uint32_t Cyc_utf8_validate(char *str, size_t len) {
     return state;
 }
 
+int uint32_num_bytes(uint32_t x) {
+  // TODO: could compute log(val) / log(256)
+  if (x < 0x100) return 1;
+  if (x < 0x10000) return 2;
+  if (x < 0x1000000) return 3;
+  return 4;
+}
+
 ////////////// END UTF-8 Section //////////////