diff --git a/vm/os-freebsd.h b/vm/os-freebsd.h
index 5cedbc82b7..c535e2d71f 100644
--- a/vm/os-freebsd.h
+++ b/vm/os-freebsd.h
@@ -10,7 +10,3 @@ extern int getosreldate(void);
 
 #define UNKNOWN_TYPE_P(file) ((file)->d_type == DT_UNKNOWN)
 #define DIRECTORY_P(file) ((file)->d_type == DT_DIR)
-
-#ifndef environ
-	extern char **environ;
-#endif
diff --git a/vm/os-linux.h b/vm/os-linux.h
index 1a1e088359..78ecbafd35 100644
--- a/vm/os-linux.h
+++ b/vm/os-linux.h
@@ -3,10 +3,6 @@
 #define UNKNOWN_TYPE_P(file) ((file)->d_type == DT_UNKNOWN)
 #define DIRECTORY_P(file) ((file)->d_type == DT_DIR)
 
-#ifndef environ
-	extern char **environ;
-#endif
-
 int inotify_init(void);
 int inotify_add_watch(int fd, const char *name, u32 mask);
 int inotify_rm_watch(int fd, u32 wd);
diff --git a/vm/os-macosx.h b/vm/os-macosx.h
index 701bb8da01..b9686a5a85 100644
--- a/vm/os-macosx.h
+++ b/vm/os-macosx.h
@@ -12,11 +12,6 @@ const char *default_image_path(void);
 
 DLLEXPORT void c_to_factor_toplevel(CELL quot);
 
-#ifndef environ
-	extern char ***_NSGetEnviron(void);
-	#define environ (*_NSGetEnviron())
-#endif
-
 INLINE void *ucontext_stack_pointer(void *uap)
 {
 	ucontext_t *ucontext = (ucontext_t *)uap;
diff --git a/vm/os-netbsd.h b/vm/os-netbsd.h
index b42c6b9d7e..54b5d0bcff 100644
--- a/vm/os-netbsd.h
+++ b/vm/os-netbsd.h
@@ -4,5 +4,3 @@
 
 #define UNKNOWN_TYPE_P(file) ((file)->d_type == DT_UNKNOWN)
 #define DIRECTORY_P(file) ((file)->d_type == DT_DIR)
-
-extern char **environ;
diff --git a/vm/os-openbsd.h b/vm/os-openbsd.h
index 21e34c98f8..af47f7bcea 100644
--- a/vm/os-openbsd.h
+++ b/vm/os-openbsd.h
@@ -1,6 +1,2 @@
 #define UNKNOWN_TYPE_P(file) ((file)->d_type == DT_UNKNOWN)
 #define DIRECTORY_P(file) ((file)->d_type == DT_DIR)
-
-#ifndef environ
-	extern char **environ;
-#endif
diff --git a/vm/os-solaris.h b/vm/os-solaris.h
index 909cc3f4e9..788a78090b 100644
--- a/vm/os-solaris.h
+++ b/vm/os-solaris.h
@@ -1,4 +1,2 @@
 #define UNKNOWN_TYPE_P(file) 1
 #define DIRECTORY_P(file) 0
-
-extern char **environ;
diff --git a/vm/os-unix.c b/vm/os-unix.c
index d4aebad537..fa2d5bb40c 100755
--- a/vm/os-unix.c
+++ b/vm/os-unix.c
@@ -99,72 +99,6 @@ DEFINE_PRIMITIVE(read_dir)
 	dpush(result);
 }
 
-DEFINE_PRIMITIVE(os_env)
-{
-	char *name = unbox_char_string();
-	char *value = getenv(name);
-	if(value == NULL)
-		dpush(F);
-	else
-		box_char_string(value);
-}
-
-DEFINE_PRIMITIVE(os_envs)
-{
-	GROWABLE_ARRAY(result);
-	REGISTER_ROOT(result);
-	char **env = environ;
-
-	while(*env)
-	{
-		CELL string = tag_object(from_char_string(*env));
-		GROWABLE_ARRAY_ADD(result,string);
-		env++;
-	}
-
-	UNREGISTER_ROOT(result);
-	GROWABLE_ARRAY_TRIM(result);
-	dpush(result);
-}
-
-DEFINE_PRIMITIVE(set_os_env)
-{
-	char *key = unbox_char_string();
-	REGISTER_C_STRING(key);
-	char *value = unbox_char_string();
-	UNREGISTER_C_STRING(key);
-	setenv(key, value, 1);
-}
-
-DEFINE_PRIMITIVE(unset_os_env)
-{
-	char *key = unbox_char_string();
-	unsetenv(key);
-}
-
-DEFINE_PRIMITIVE(set_os_envs)
-{
-	F_ARRAY *array = untag_array(dpop());
-	CELL size = array_capacity(array);
-
-	/* Memory leak */
-	char **env = calloc(size + 1,sizeof(CELL));
-
-	CELL i;
-	for(i = 0; i < size; i++)
-	{
-		F_STRING *string = untag_string(array_nth(array,i));
-		CELL length = to_fixnum(string->length);
-
-		char *chars = malloc(length + 1);
-		char_string_to_memory(string,chars);
-		chars[length] = '\0';
-		env[i] = chars;
-	}
-
-	environ = env;
-}
-
 F_SEGMENT *alloc_segment(CELL size)
 {
 	int pagesize = getpagesize();
diff --git a/vm/os-windows.c b/vm/os-windows.c
index 4c21c9b5c9..c36ba59a27 100755
--- a/vm/os-windows.c
+++ b/vm/os-windows.c
@@ -214,38 +214,3 @@ void sleep_millis(DWORD msec)
 {
 	Sleep(msec);
 }
-
-DEFINE_PRIMITIVE(os_env)
-{
-	F_CHAR *key = unbox_u16_string();
-	F_CHAR *value = safe_malloc(MAX_UNICODE_PATH * 2);
-	int ret;
-	ret = GetEnvironmentVariable(key, value, MAX_UNICODE_PATH * 2);
-	if(ret == 0)
-		dpush(F);
-	else
-		dpush(tag_object(from_u16_string(value)));
-	free(value);
-}
-
-DEFINE_PRIMITIVE(set_os_env)
-{
-	F_CHAR *key = unbox_u16_string();
-	REGISTER_C_STRING(key);
-	F_CHAR *value = unbox_u16_string();
-	UNREGISTER_C_STRING(key);
-	if(!SetEnvironmentVariable(key, value))
-		general_error(ERROR_IO, tag_object(get_error_message()), F, NULL);
-}
-
-DEFINE_PRIMITIVE(unset_os_env)
-{
-	if(!SetEnvironmentVariable(unbox_u16_string(), NULL)
-		&& GetLastError() != ERROR_ENVVAR_NOT_FOUND)
-		general_error(ERROR_IO, tag_object(get_error_message()), F, NULL);
-}
-
-DEFINE_PRIMITIVE(set_os_envs)
-{
-	not_implemented_error();
-}
diff --git a/vm/primitives.c b/vm/primitives.c
index b5d9403342..39dc2b10d7 100755
--- a/vm/primitives.c
+++ b/vm/primitives.c
@@ -71,7 +71,6 @@ void *primitives[] = {
 	primitive_exit,
 	primitive_data_room,
 	primitive_code_room,
-	primitive_os_env,
 	primitive_millis,
 	primitive_modify_code_heap,
 	primitive_dlopen,
@@ -141,10 +140,6 @@ void *primitives[] = {
 	primitive_innermost_stack_frame_scan,
 	primitive_set_innermost_stack_frame_quot,
 	primitive_call_clear,
-	primitive_os_envs,
-	primitive_set_os_env,
-	primitive_unset_os_env,
-	primitive_set_os_envs,
 	primitive_resize_byte_array,
 	primitive_dll_validp,
 	primitive_unimplemented,