diff --git a/py/compile.c b/py/compile.c
index 0c43d939e1..f925c8c1ff 100644
--- a/py/compile.c
+++ b/py/compile.c
@@ -56,6 +56,7 @@ typedef enum {
 #include "grammar.h"
 #undef DEF_RULE
     PN_maximum_number_of,
+    PN_string, // special node for non-interned string
 } pn_kind_t;
 
 #define EMIT(fun) (comp->emit_method_table->fun(comp->emit))
@@ -177,6 +178,8 @@ STATIC mp_parse_node_t fold_constants(compiler_t *comp, mp_parse_node_t pn, mp_m
                 }
                 break;
 #endif
+            case PN_string:
+                return pn;
         }
 
         // fold arguments
@@ -426,6 +429,9 @@ void compile_generic_all_nodes(compiler_t *comp, mp_parse_node_struct_t *pns) {
 
 #if MICROPY_EMIT_CPYTHON
 STATIC bool cpython_c_tuple_is_const(mp_parse_node_t pn) {
+    if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, PN_string)) {
+        return true;
+    }
     if (!MP_PARSE_NODE_IS_LEAF(pn)) {
         return false;
     }
@@ -435,9 +441,7 @@ STATIC bool cpython_c_tuple_is_const(mp_parse_node_t pn) {
     return true;
 }
 
-STATIC void cpython_c_print_quoted_str(vstr_t *vstr, qstr qstr, bool bytes) {
-    uint len;
-    const byte *str = qstr_data(qstr, &len);
+STATIC void cpython_c_print_quoted_str(vstr_t *vstr, const char *str, uint len, bool bytes) {
     bool has_single_quote = false;
     bool has_double_quote = false;
     for (int i = 0; i < len; i++) {
@@ -476,6 +480,12 @@ STATIC void cpython_c_print_quoted_str(vstr_t *vstr, qstr qstr, bool bytes) {
 }
 
 STATIC void cpython_c_tuple_emit_const(compiler_t *comp, mp_parse_node_t pn, vstr_t *vstr) {
+    if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, PN_string)) {
+        mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
+        cpython_c_print_quoted_str(vstr, (const char*)pns->nodes[0], (machine_uint_t)pns->nodes[1], false);
+        return;
+    }
+
     assert(MP_PARSE_NODE_IS_LEAF(pn));
     if (MP_PARSE_NODE_IS_SMALL_INT(pn)) {
         vstr_printf(vstr, INT_FMT, MP_PARSE_NODE_LEAF_SMALL_INT(pn));
@@ -487,8 +497,13 @@ STATIC void cpython_c_tuple_emit_const(compiler_t *comp, mp_parse_node_t pn, vst
         case MP_PARSE_NODE_ID: assert(0);
         case MP_PARSE_NODE_INTEGER: vstr_printf(vstr, "%s", qstr_str(arg)); break;
         case MP_PARSE_NODE_DECIMAL: vstr_printf(vstr, "%s", qstr_str(arg)); break;
-        case MP_PARSE_NODE_STRING: cpython_c_print_quoted_str(vstr, arg, false); break;
-        case MP_PARSE_NODE_BYTES: cpython_c_print_quoted_str(vstr, arg, true); break;
+        case MP_PARSE_NODE_STRING:
+        case MP_PARSE_NODE_BYTES: {
+            uint len;
+            const byte *str = qstr_data(arg, &len);
+            cpython_c_print_quoted_str(vstr, (const char*)str, len, MP_PARSE_NODE_LEAF_KIND(pn) == MP_PARSE_NODE_BYTES);
+            break;
+        }
         case MP_PARSE_NODE_TOKEN:
             switch (arg) {
                 case MP_TOKEN_KW_FALSE: vstr_printf(vstr, "False"); break;
@@ -2058,7 +2073,8 @@ void compile_expr_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) {
 
         } else {
             // for non-REPL, evaluate then discard the expression
-            if (MP_PARSE_NODE_IS_LEAF(pns->nodes[0]) && !MP_PARSE_NODE_IS_ID(pns->nodes[0])) {
+            if ((MP_PARSE_NODE_IS_LEAF(pns->nodes[0]) && !MP_PARSE_NODE_IS_ID(pns->nodes[0]))
+                || MP_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[0], PN_string)) {
                 // do nothing with a lonely constant
             } else {
                 compile_node(comp, pns->nodes[0]); // just an expression
@@ -2498,26 +2514,40 @@ void compile_atom_string(compiler_t *comp, mp_parse_node_struct_t *pns) {
     int n_bytes = 0;
     int string_kind = MP_PARSE_NODE_NULL;
     for (int i = 0; i < n; i++) {
-        assert(MP_PARSE_NODE_IS_LEAF(pns->nodes[i]));
-        int pn_kind = MP_PARSE_NODE_LEAF_KIND(pns->nodes[i]);
-        assert(pn_kind == MP_PARSE_NODE_STRING || pn_kind == MP_PARSE_NODE_BYTES);
+        int pn_kind;
+        if (MP_PARSE_NODE_IS_LEAF(pns->nodes[i])) {
+            pn_kind = MP_PARSE_NODE_LEAF_KIND(pns->nodes[i]);
+            assert(pn_kind == MP_PARSE_NODE_STRING || pn_kind == MP_PARSE_NODE_BYTES);
+            n_bytes += qstr_len(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]));
+        } else {
+            assert(MP_PARSE_NODE_IS_STRUCT(pns->nodes[i]));
+            mp_parse_node_struct_t *pns_string = (mp_parse_node_struct_t*)pns->nodes[i];
+            assert(MP_PARSE_NODE_STRUCT_KIND(pns_string) == PN_string);
+            pn_kind = MP_PARSE_NODE_STRING;
+            n_bytes += (machine_uint_t)pns_string->nodes[1];
+        }
         if (i == 0) {
             string_kind = pn_kind;
         } else if (pn_kind != string_kind) {
             compile_syntax_error(comp, (mp_parse_node_t)pns, "cannot mix bytes and nonbytes literals");
             return;
         }
-        n_bytes += qstr_len(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]));
     }
 
     // concatenate string/bytes
     byte *q_ptr;
     byte *s_dest = qstr_build_start(n_bytes, &q_ptr);
     for (int i = 0; i < n; i++) {
-        uint s_len;
-        const byte *s = qstr_data(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]), &s_len);
-        memcpy(s_dest, s, s_len);
-        s_dest += s_len;
+        if (MP_PARSE_NODE_IS_LEAF(pns->nodes[i])) {
+            uint s_len;
+            const byte *s = qstr_data(MP_PARSE_NODE_LEAF_ARG(pns->nodes[i]), &s_len);
+            memcpy(s_dest, s, s_len);
+            s_dest += s_len;
+        } else {
+            mp_parse_node_struct_t *pns_string = (mp_parse_node_struct_t*)pns->nodes[i];
+            memcpy(s_dest, (const char*)pns_string->nodes[0], (machine_uint_t)pns_string->nodes[1]);
+            s_dest += (machine_uint_t)pns_string->nodes[1];
+        }
     }
     qstr q = qstr_build_end(q_ptr);
 
@@ -2848,15 +2878,19 @@ void compile_node(compiler_t *comp, mp_parse_node_t pn) {
     } else {
         mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
         EMIT_ARG(set_line_number, pns->source_line);
-        compile_function_t f = compile_function[MP_PARSE_NODE_STRUCT_KIND(pns)];
-        if (f == NULL) {
-            printf("node %u cannot be compiled\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns));
-#if MICROPY_DEBUG_PRINTERS
-            mp_parse_node_print(pn, 0);
-#endif
-            compile_syntax_error(comp, pn, "internal compiler error");
+        if (MP_PARSE_NODE_STRUCT_KIND(pns) == PN_string) {
+            EMIT_ARG(load_const_str, qstr_from_strn((const char*)pns->nodes[0], (machine_uint_t)pns->nodes[1]), false);
         } else {
-            f(comp, pns);
+            compile_function_t f = compile_function[MP_PARSE_NODE_STRUCT_KIND(pns)];
+            if (f == NULL) {
+                printf("node %u cannot be compiled\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns));
+#if MICROPY_DEBUG_PRINTERS
+                mp_parse_node_print(pn, 0);
+#endif
+                compile_syntax_error(comp, pn, "internal compiler error");
+            } else {
+                f(comp, pns);
+            }
         }
     }
 }
@@ -3033,13 +3067,13 @@ STATIC void check_for_doc_string(compiler_t *comp, mp_parse_node_t pn) {
     // check the first statement for a doc string
     if (MP_PARSE_NODE_IS_STRUCT_KIND(pn, PN_expr_stmt)) {
         mp_parse_node_struct_t* pns = (mp_parse_node_struct_t*)pn;
-        if (MP_PARSE_NODE_IS_LEAF(pns->nodes[0])) {
-            int kind = MP_PARSE_NODE_LEAF_KIND(pns->nodes[0]);
-            if (kind == MP_PARSE_NODE_STRING) {
-                compile_node(comp, pns->nodes[0]); // a doc string
-                // store doc string
+        if ((MP_PARSE_NODE_IS_LEAF(pns->nodes[0])
+                && MP_PARSE_NODE_LEAF_KIND(pns->nodes[0]) == MP_PARSE_NODE_STRING)
+            || MP_PARSE_NODE_IS_STRUCT_KIND(pns->nodes[0], PN_string)) {
+                // compile the doc string
+                compile_node(comp, pns->nodes[0]);
+                // store the doc string
                 EMIT_ARG(store_id, MP_QSTR___doc__);
-            }
         }
     }
 #endif
diff --git a/py/mpconfig.h b/py/mpconfig.h
index 853d475c3e..1af27f7679 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -66,6 +66,11 @@
 #define MICROPY_ALLOC_PARSE_RESULT_INC (16)
 #endif
 
+// Strings this length or less will be interned by the parser
+#ifndef MICROPY_ALLOC_PARSE_INTERN_STRING_LEN
+#define MICROPY_ALLOC_PARSE_INTERN_STRING_LEN (10)
+#endif
+
 // Initial amount for ids in a scope
 #ifndef MICROPY_ALLOC_SCOPE_ID_INIT
 #define MICROPY_ALLOC_SCOPE_ID_INIT (4)
diff --git a/py/parse.c b/py/parse.c
index 4bc78f14a9..b255ebd35c 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -28,6 +28,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <assert.h>
+#include <string.h>
 
 #include "misc.h"
 #include "mpconfig.h"
@@ -70,6 +71,7 @@ enum {
 #include "grammar.h"
 #undef DEF_RULE
     RULE_maximum_number_of,
+    RULE_string, // special node for non-interned string
 };
 
 #define or(n)                   (RULE_ACT_OR | n)
@@ -170,26 +172,26 @@ mp_parse_node_t mp_parse_node_new_leaf(machine_int_t kind, machine_int_t arg) {
     return (mp_parse_node_t)(kind | (arg << 5));
 }
 
-uint mp_parse_node_free(mp_parse_node_t pn) {
-    uint cnt = 0;
+void mp_parse_node_free(mp_parse_node_t pn) {
     if (MP_PARSE_NODE_IS_STRUCT(pn)) {
         mp_parse_node_struct_t *pns = (mp_parse_node_struct_t *)pn;
         uint n = MP_PARSE_NODE_STRUCT_NUM_NODES(pns);
         uint rule_id = MP_PARSE_NODE_STRUCT_KIND(pns);
+        if (rule_id == RULE_string) {
+            return;
+        }
         bool adjust = ADD_BLANK_NODE(rule_id);
         if (adjust) {
             n--;
         }
         for (uint i = 0; i < n; i++) {
-            cnt += mp_parse_node_free(pns->nodes[i]);
+            mp_parse_node_free(pns->nodes[i]);
         }
         if (adjust) {
             n++;
         }
         m_del_var(mp_parse_node_struct_t, mp_parse_node_t, n, pns);
-        cnt++;
     }
-    return cnt;
 }
 
 #if MICROPY_DEBUG_PRINTERS
@@ -219,15 +221,20 @@ void mp_parse_node_print(mp_parse_node_t pn, int indent) {
             default: assert(0);
         }
     } else {
+        // node must be a mp_parse_node_struct_t
         mp_parse_node_struct_t *pns = (mp_parse_node_struct_t*)pn;
-        uint n = MP_PARSE_NODE_STRUCT_NUM_NODES(pns);
+        if (MP_PARSE_NODE_STRUCT_KIND(pns) == RULE_string) {
+            printf("literal str(%.*s)\n", (int)pns->nodes[1], (char*)pns->nodes[0]);
+        } else {
+            uint n = MP_PARSE_NODE_STRUCT_NUM_NODES(pns);
 #ifdef USE_RULE_NAME
-        printf("%s(%d) (n=%d)\n", rules[MP_PARSE_NODE_STRUCT_KIND(pns)]->rule_name, MP_PARSE_NODE_STRUCT_KIND(pns), n);
+            printf("%s(%d) (n=%d)\n", rules[MP_PARSE_NODE_STRUCT_KIND(pns)]->rule_name, MP_PARSE_NODE_STRUCT_KIND(pns), n);
 #else
-        printf("rule(%u) (n=%d)\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns), n);
+            printf("rule(%u) (n=%d)\n", (uint)MP_PARSE_NODE_STRUCT_KIND(pns), n);
 #endif
-        for (uint i = 0; i < n; i++) {
-            mp_parse_node_print(pns->nodes[i], indent + 2);
+            for (uint i = 0; i < n; i++) {
+                mp_parse_node_print(pns->nodes[i], indent + 2);
+            }
         }
     }
 }
@@ -274,6 +281,21 @@ STATIC void push_result_node(parser_t *parser, mp_parse_node_t pn) {
     parser->result_stack[parser->result_stack_top++] = pn;
 }
 
+STATIC void push_result_string(parser_t *parser, int src_line, const char *str, uint len) {
+    mp_parse_node_struct_t *pn = m_new_obj_var_maybe(mp_parse_node_struct_t, mp_parse_node_t, 2);
+    if (pn == NULL) {
+        memory_error(parser);
+        return;
+    }
+    pn->source_line = src_line;
+    pn->kind_num_nodes = RULE_string | (2 << 8);
+    char *p = m_new(char, len);
+    memcpy(p, str, len);
+    pn->nodes[0] = (machine_int_t)p;
+    pn->nodes[1] = len;
+    push_result_node(parser, (mp_parse_node_t)pn);
+}
+
 STATIC void push_result_token(parser_t *parser, const mp_lexer_t *lex) {
     const mp_token_t *tok = mp_lexer_cur(lex);
     mp_parse_node_t pn;
@@ -319,7 +341,24 @@ STATIC void push_result_token(parser_t *parser, const mp_lexer_t *lex) {
             pn = mp_parse_node_new_leaf(MP_PARSE_NODE_INTEGER, qstr_from_strn(str, len));
         }
     } else if (tok->kind == MP_TOKEN_STRING) {
-        pn = mp_parse_node_new_leaf(MP_PARSE_NODE_STRING, qstr_from_strn(tok->str, tok->len));
+        // Don't automatically intern all strings.  doc strings (which are usually large)
+        // will be discarded by the compiler, and so we shouldn't intern them.
+        qstr qst = MP_QSTR_NULL;
+        if (tok->len <= MICROPY_ALLOC_PARSE_INTERN_STRING_LEN) {
+            // intern short strings
+            qst = qstr_from_strn(tok->str, tok->len);
+        } else {
+            // check if this string is already interned
+            qst = qstr_find_strn((const byte*)tok->str, tok->len);
+        }
+        if (qst != MP_QSTR_NULL) {
+            // qstr exists, make a leaf node
+            pn = mp_parse_node_new_leaf(MP_PARSE_NODE_STRING, qst);
+        } else {
+            // not interned, make a node holding a pointer to the string data
+            push_result_string(parser, mp_lexer_cur(lex)->src_line, tok->str, tok->len);
+            return;
+        }
     } else if (tok->kind == MP_TOKEN_BYTES) {
         pn = mp_parse_node_new_leaf(MP_PARSE_NODE_BYTES, qstr_from_strn(tok->str, tok->len));
     } else {
@@ -516,14 +555,13 @@ mp_parse_node_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, mp_p
                     }
                 }
 
-#if 0 && !MICROPY_ENABLE_DOC_STRING
-                // this code discards lonely statement, such as doc strings
-                // problem is that doc strings have already been interned, so this doesn't really help reduce RAM usage
+#if !MICROPY_EMIT_CPYTHON && !MICROPY_ENABLE_DOC_STRING
+                // this code discards lonely statements, such as doc strings
                 if (input_kind != MP_PARSE_SINGLE_INPUT && rule->rule_id == RULE_expr_stmt && peek_result(&parser, 0) == MP_PARSE_NODE_NULL) {
                     mp_parse_node_t p = peek_result(&parser, 1);
-                    if (MP_PARSE_NODE_IS_LEAF(p) && !MP_PARSE_NODE_IS_ID(p)) {
-                        pop_result(parser);
-                        pop_result(parser);
+                    if ((MP_PARSE_NODE_IS_LEAF(p) && !MP_PARSE_NODE_IS_ID(p)) || MP_PARSE_NODE_IS_STRUCT_KIND(p, RULE_string)) {
+                        pop_result(&parser);
+                        pop_result(&parser);
                         push_result_rule(&parser, rule_src_line, rules[RULE_pass_stmt], 0);
                         break;
                     }
diff --git a/py/parse.h b/py/parse.h
index 41102e1600..43c74e73b8 100644
--- a/py/parse.h
+++ b/py/parse.h
@@ -82,7 +82,7 @@ typedef struct _mp_parse_node_struct_t {
 #define MP_PARSE_NODE_STRUCT_NUM_NODES(pns) ((pns)->kind_num_nodes >> 8)
 
 mp_parse_node_t mp_parse_node_new_leaf(machine_int_t kind, machine_int_t arg);
-uint mp_parse_node_free(mp_parse_node_t pn);
+void mp_parse_node_free(mp_parse_node_t pn);
 
 void mp_parse_node_print(mp_parse_node_t pn, int indent);