diff --git a/build-aux/configure-lib.sh b/build-aux/configure-lib.sh
index 0f09d489..609dcaff 100644
--- a/build-aux/configure-lib.sh
+++ b/build-aux/configure-lib.sh
@@ -439,6 +439,7 @@ src/core.c
 src/display.c
 src/eval-apply.c
 src/gc.c
+src/globals.c
 src/hash.c
 src/lib.c
 src/math.c
diff --git a/include/mes/mes.h b/include/mes/mes.h
index 90abe592..9ef6491e 100644
--- a/include/mes/mes.h
+++ b/include/mes/mes.h
@@ -54,59 +54,59 @@ struct scm
 };
 
 /* mes */
-char *g_datadir;
-int g_debug;
-char *g_buf;
-int g_continuations;
-struct scm *g_symbols;
-struct scm *g_symbol_max;
-int g_mini;
+extern char *g_datadir;
+extern int g_debug;
+extern char *g_buf;
+extern int g_continuations;
+extern struct scm *g_symbols;
+extern struct scm *g_symbol_max;
+extern int g_mini;
 
 /* a/env */
-struct scm *R0;
+extern struct scm *R0;
 /* param 1 */
-struct scm *R1;
+extern struct scm *R1;
 /* save 2 */
-struct scm *R2;
+extern struct scm *R2;
 /* continuation */
-struct scm *R3;
+extern struct scm *R3;
 /* current-module */
-struct scm *M0;
+extern struct scm *M0;
 /* macro */
-struct scm *g_macros;
-struct scm *g_ports;
+extern struct scm *g_macros;
+extern struct scm *g_ports;
 
 /* gc */
-size_t ARENA_SIZE;
-size_t MAX_ARENA_SIZE;
-size_t STACK_SIZE;
-size_t JAM_SIZE;
-size_t GC_SAFETY;
-size_t MAX_STRING;
-char *g_arena;
-struct scm *cell_arena;
-struct scm *cell_zero;
+extern size_t ARENA_SIZE;
+extern size_t MAX_ARENA_SIZE;
+extern size_t STACK_SIZE;
+extern size_t JAM_SIZE;
+extern size_t GC_SAFETY;
+extern size_t MAX_STRING;
+extern char *g_arena;
+extern struct scm *cell_arena;
+extern struct scm *cell_zero;
 
-struct scm *g_free;
-struct scm *g_symbol;
+extern struct scm *g_free;
+extern struct scm *g_symbol;
 
-struct scm **g_stack_array;
-struct scm *g_cells;
-struct scm *g_news;
-long g_stack;
-size_t gc_count;
-struct timespec *gc_start_time;
-struct timespec *gc_end_time;
-size_t gc_time;
+extern struct scm **g_stack_array;
+extern struct scm *g_cells;
+extern struct scm *g_news;
+extern long g_stack;
+extern size_t gc_count;
+extern struct timespec *gc_start_time;
+extern struct timespec *gc_end_time;
+extern size_t gc_time;
 
-char **__execl_c_argv;
-char *__open_boot_buf;
-char *__open_boot_file_name;
-char *__setenv_buf;
-char *__reader_read_char_buf;
-struct timespec *g_start_time;
-struct timeval *__gettimeofday_time;
-struct timespec *__get_internal_run_time_ts;
+extern char **__execl_c_argv;
+extern char *__open_boot_buf;
+extern char *__open_boot_file_name;
+extern char *__setenv_buf;
+extern char *__reader_read_char_buf;
+extern struct timespec *g_start_time;
+extern struct timeval *__gettimeofday_time;
+extern struct timespec *__get_internal_run_time_ts;
 
 struct scm *cast_charp_to_scmp (char const *i);
 struct scm **cast_charp_to_scmpp (char const *i);
diff --git a/include/mes/symbols.h b/include/mes/symbols.h
index ec185bdc..490fa1e2 100644
--- a/include/mes/symbols.h
+++ b/include/mes/symbols.h
@@ -1,6 +1,6 @@
 /* -*-comment-start: "//";comment-end:""-*-
  * GNU Mes --- Maxwell Equations of Software
- * Copyright © 2016,2017,2018,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ * Copyright © 2016,2017,2018,2019,2021 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
  *
  * This file is part of GNU Mes.
  *
@@ -21,121 +21,121 @@
 #ifndef __MES_SYMBOLS_H
 #define __MES_SYMBOLS_H
 
-struct scm *cell_nil;
-struct scm *cell_f;
-struct scm *cell_t;
-struct scm *cell_dot;
-struct scm *cell_arrow;
-struct scm *cell_undefined;
-struct scm *cell_unspecified;
-struct scm *cell_closure;
-struct scm *cell_circular;
+extern struct scm *cell_nil;
+extern struct scm *cell_f;
+extern struct scm *cell_t;
+extern struct scm *cell_dot;
+extern struct scm *cell_arrow;
+extern struct scm *cell_undefined;
+extern struct scm *cell_unspecified;
+extern struct scm *cell_closure;
+extern struct scm *cell_circular;
 
-struct scm *cell_vm_apply;
-struct scm *cell_vm_apply2;
-struct scm *cell_vm_begin;
-struct scm *cell_vm_begin_eval;
-struct scm *cell_vm_begin_expand;
-struct scm *cell_vm_begin_expand_eval;
-struct scm *cell_vm_begin_expand_macro;
-struct scm *cell_vm_begin_expand_primitive_load;
-struct scm *cell_vm_begin_primitive_load;
-struct scm *cell_vm_begin_read_input_file;
-struct scm *cell_vm_call_with_current_continuation2;
-struct scm *cell_vm_call_with_values2;
-struct scm *cell_vm_eval;
-struct scm *cell_vm_eval2;
-struct scm *cell_vm_eval_check_func;
-struct scm *cell_vm_eval_define;
-struct scm *cell_vm_eval_macro_expand_eval;
-struct scm *cell_vm_eval_macro_expand_expand;
-struct scm *cell_vm_eval_pmatch_car;
-struct scm *cell_vm_eval_pmatch_cdr;
-struct scm *cell_vm_eval_set_x;
-struct scm *cell_vm_evlis;
-struct scm *cell_vm_evlis2;
-struct scm *cell_vm_evlis3;
-struct scm *cell_vm_if;
-struct scm *cell_vm_if_expr;
-struct scm *cell_vm_macro_expand;
-struct scm *cell_vm_macro_expand_car;
-struct scm *cell_vm_macro_expand_cdr;
-struct scm *cell_vm_macro_expand_define;
-struct scm *cell_vm_macro_expand_define_macro;
-struct scm *cell_vm_macro_expand_lambda;
-struct scm *cell_vm_macro_expand_set_x;
-struct scm *cell_vm_return;
+extern struct scm *cell_vm_apply;
+extern struct scm *cell_vm_apply2;
+extern struct scm *cell_vm_begin;
+extern struct scm *cell_vm_begin_eval;
+extern struct scm *cell_vm_begin_expand;
+extern struct scm *cell_vm_begin_expand_eval;
+extern struct scm *cell_vm_begin_expand_macro;
+extern struct scm *cell_vm_begin_expand_primitive_load;
+extern struct scm *cell_vm_begin_primitive_load;
+extern struct scm *cell_vm_begin_read_input_file;
+extern struct scm *cell_vm_call_with_current_continuation2;
+extern struct scm *cell_vm_call_with_values2;
+extern struct scm *cell_vm_eval;
+extern struct scm *cell_vm_eval2;
+extern struct scm *cell_vm_eval_check_func;
+extern struct scm *cell_vm_eval_define;
+extern struct scm *cell_vm_eval_macro_expand_eval;
+extern struct scm *cell_vm_eval_macro_expand_expand;
+extern struct scm *cell_vm_eval_pmatch_car;
+extern struct scm *cell_vm_eval_pmatch_cdr;
+extern struct scm *cell_vm_eval_set_x;
+extern struct scm *cell_vm_evlis;
+extern struct scm *cell_vm_evlis2;
+extern struct scm *cell_vm_evlis3;
+extern struct scm *cell_vm_if;
+extern struct scm *cell_vm_if_expr;
+extern struct scm *cell_vm_macro_expand;
+extern struct scm *cell_vm_macro_expand_car;
+extern struct scm *cell_vm_macro_expand_cdr;
+extern struct scm *cell_vm_macro_expand_define;
+extern struct scm *cell_vm_macro_expand_define_macro;
+extern struct scm *cell_vm_macro_expand_lambda;
+extern struct scm *cell_vm_macro_expand_set_x;
+extern struct scm *cell_vm_return;
 
-struct scm *cell_symbol_lambda;
-struct scm *cell_symbol_begin;
-struct scm *cell_symbol_if;
-struct scm *cell_symbol_quote;
-struct scm *cell_symbol_define;
-struct scm *cell_symbol_define_macro;
-struct scm *cell_symbol_quasiquote;
-struct scm *cell_symbol_unquote;
-struct scm *cell_symbol_unquote_splicing;
-struct scm *cell_symbol_syntax;
-struct scm *cell_symbol_quasisyntax;
-struct scm *cell_symbol_unsyntax;
-struct scm *cell_symbol_unsyntax_splicing;
-struct scm *cell_symbol_set_x;
-struct scm *cell_symbol_sc_expand;
-struct scm *cell_symbol_macro_expand;
-struct scm *cell_symbol_portable_macro_expand;
-struct scm *cell_symbol_sc_expander_alist;
-struct scm *cell_symbol_call_with_values;
-struct scm *cell_symbol_call_with_current_continuation;
-struct scm *cell_symbol_boot_module;
-struct scm *cell_symbol_current_module;
-struct scm *cell_symbol_primitive_load;
-struct scm *cell_symbol_car;
-struct scm *cell_symbol_cdr;
-struct scm *cell_symbol_not_a_number;
-struct scm *cell_symbol_not_a_pair;
-struct scm *cell_symbol_system_error;
-struct scm *cell_symbol_throw;
-struct scm *cell_symbol_unbound_variable;
-struct scm *cell_symbol_wrong_number_of_args;
-struct scm *cell_symbol_wrong_type_arg;
-struct scm *cell_symbol_buckets;
-struct scm *cell_symbol_builtin;
-struct scm *cell_symbol_frame;
-struct scm *cell_symbol_hashq_table;
-struct scm *cell_symbol_module;
-struct scm *cell_symbol_procedure;
-struct scm *cell_symbol_record_type;
-struct scm *cell_symbol_size;
-struct scm *cell_symbol_stack;
-struct scm *cell_symbol_argv;
-struct scm *cell_symbol_mes_datadir;
-struct scm *cell_symbol_mes_version;
-struct scm *cell_symbol_internal_time_units_per_second;
-struct scm *cell_symbol_compiler;
-struct scm *cell_symbol_arch;
-struct scm *cell_symbol_pmatch_car;
-struct scm *cell_symbol_pmatch_cdr;
-struct scm *cell_type_bytes;
-struct scm *cell_type_char;
-struct scm *cell_type_closure;
-struct scm *cell_type_continuation;
-struct scm *cell_type_function;
-struct scm *cell_type_keyword;
-struct scm *cell_type_macro;
-struct scm *cell_type_number;
-struct scm *cell_type_pair;
-struct scm *cell_type_port;
-struct scm *cell_type_ref;
-struct scm *cell_type_special;
-struct scm *cell_type_string;
-struct scm *cell_type_struct;
-struct scm *cell_type_symbol;
-struct scm *cell_type_values;
-struct scm *cell_type_variable;
-struct scm *cell_type_vector;
-struct scm *cell_type_broken_heart;
-struct scm *cell_symbol_program;
-struct scm *cell_symbol_test;
+extern struct scm *cell_symbol_lambda;
+extern struct scm *cell_symbol_begin;
+extern struct scm *cell_symbol_if;
+extern struct scm *cell_symbol_quote;
+extern struct scm *cell_symbol_define;
+extern struct scm *cell_symbol_define_macro;
+extern struct scm *cell_symbol_quasiquote;
+extern struct scm *cell_symbol_unquote;
+extern struct scm *cell_symbol_unquote_splicing;
+extern struct scm *cell_symbol_syntax;
+extern struct scm *cell_symbol_quasisyntax;
+extern struct scm *cell_symbol_unsyntax;
+extern struct scm *cell_symbol_unsyntax_splicing;
+extern struct scm *cell_symbol_set_x;
+extern struct scm *cell_symbol_sc_expand;
+extern struct scm *cell_symbol_macro_expand;
+extern struct scm *cell_symbol_portable_macro_expand;
+extern struct scm *cell_symbol_sc_expander_alist;
+extern struct scm *cell_symbol_call_with_values;
+extern struct scm *cell_symbol_call_with_current_continuation;
+extern struct scm *cell_symbol_boot_module;
+extern struct scm *cell_symbol_current_module;
+extern struct scm *cell_symbol_primitive_load;
+extern struct scm *cell_symbol_car;
+extern struct scm *cell_symbol_cdr;
+extern struct scm *cell_symbol_not_a_number;
+extern struct scm *cell_symbol_not_a_pair;
+extern struct scm *cell_symbol_system_error;
+extern struct scm *cell_symbol_throw;
+extern struct scm *cell_symbol_unbound_variable;
+extern struct scm *cell_symbol_wrong_number_of_args;
+extern struct scm *cell_symbol_wrong_type_arg;
+extern struct scm *cell_symbol_buckets;
+extern struct scm *cell_symbol_builtin;
+extern struct scm *cell_symbol_frame;
+extern struct scm *cell_symbol_hashq_table;
+extern struct scm *cell_symbol_module;
+extern struct scm *cell_symbol_procedure;
+extern struct scm *cell_symbol_record_type;
+extern struct scm *cell_symbol_size;
+extern struct scm *cell_symbol_stack;
+extern struct scm *cell_symbol_argv;
+extern struct scm *cell_symbol_mes_datadir;
+extern struct scm *cell_symbol_mes_version;
+extern struct scm *cell_symbol_internal_time_units_per_second;
+extern struct scm *cell_symbol_compiler;
+extern struct scm *cell_symbol_arch;
+extern struct scm *cell_symbol_pmatch_car;
+extern struct scm *cell_symbol_pmatch_cdr;
+extern struct scm *cell_type_bytes;
+extern struct scm *cell_type_char;
+extern struct scm *cell_type_closure;
+extern struct scm *cell_type_continuation;
+extern struct scm *cell_type_function;
+extern struct scm *cell_type_keyword;
+extern struct scm *cell_type_macro;
+extern struct scm *cell_type_number;
+extern struct scm *cell_type_pair;
+extern struct scm *cell_type_port;
+extern struct scm *cell_type_ref;
+extern struct scm *cell_type_special;
+extern struct scm *cell_type_string;
+extern struct scm *cell_type_struct;
+extern struct scm *cell_type_symbol;
+extern struct scm *cell_type_values;
+extern struct scm *cell_type_variable;
+extern struct scm *cell_type_vector;
+extern struct scm *cell_type_broken_heart;
+extern struct scm *cell_symbol_program;
+extern struct scm *cell_symbol_test;
 
 // CONSTANT SYMBOL_MAX 114
 #define SYMBOL_MAX 114
diff --git a/src/globals.c b/src/globals.c
new file mode 100644
index 00000000..43c255f3
--- /dev/null
+++ b/src/globals.c
@@ -0,0 +1,25 @@
+/*
+ * GNU Mes --- Maxwell Equations of Software
+ * Copyright © 2021 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+ *
+ * This file is part of GNU Mes.
+ *
+ * GNU Mes is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * GNU Mes is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <mes/lib-mini.h>
+
+#define extern
+#include <mes/symbols.h>
+#include <mes/mes.h>
diff --git a/src/symbol.c b/src/symbol.c
index 1b6850f5..11dc9311 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -33,8 +33,6 @@
 // CONSTANT M2_CELL_SIZE 12
 #endif
 
-struct scm *g_symbol;
-
 struct scm *
 init_symbol (struct scm *x, long type, char const *name)
 {