diff --git a/libexec/rtld-elf/rtld.h b/libexec/rtld-elf/rtld.h
--- a/libexec/rtld-elf/rtld.h
+++ b/libexec/rtld-elf/rtld.h
@@ -352,6 +352,33 @@
     struct Struct_RtldLockState *lockstate;
 } SymLook;
 
+enum {
+	LD_BIND_NOW = 0,
+	LD_PRELOAD,
+	LD_LIBMAP,
+	LD_LIBRARY_PATH,
+	LD_LIBRARY_PATH_FDS,
+	LD_LIBMAP_DISABLE,
+	LD_BIND_NOT,
+	LD_DEBUG,
+	LD_ELF_HINTS_PATH,
+	LD_LOADFLTR,
+	LD_LIBRARY_PATH_RPATH,
+	LD_PRELOAD_FDS,
+	LD_DYNAMIC_WEAK,
+	LD_TRACE_LOADED_OBJECTS,
+	LD_UTRACE,
+	LD_DUMP_REL_PRE,
+	LD_DUMP_REL_POST,
+	LD_TRACE_LOADED_OBJECTS_PROGNAME,
+	LD_TRACE_LOADED_OBJECTS_FMT1,
+	LD_TRACE_LOADED_OBJECTS_FMT2,
+	LD_TRACE_LOADED_OBJECTS_ALL,
+	LD_SHOW_AUXV,
+	LD_STATIC_TLS_EXTRA,
+	LD_NO_DL_ITERATE_PHDR_AFTER_FORK,
+};
+
 void _rtld_error(const char *, ...) __printflike(1, 2) __exported;
 void rtld_die(void) __dead2;
 const char *rtld_strerror(int);
@@ -373,6 +400,7 @@
 /*
  * Function declarations.
  */
+const char *ld_get_env_var(int idx);
 uintptr_t rtld_round_page(uintptr_t);
 uintptr_t rtld_trunc_page(uintptr_t);
 Elf32_Word elf_hash(const char *);
diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -343,32 +343,6 @@
 	utrace(&ut, sizeof(ut));
 }
 
-enum {
-	LD_BIND_NOW = 0,
-	LD_PRELOAD,
-	LD_LIBMAP,
-	LD_LIBRARY_PATH,
-	LD_LIBRARY_PATH_FDS,
-	LD_LIBMAP_DISABLE,
-	LD_BIND_NOT,
-	LD_DEBUG,
-	LD_ELF_HINTS_PATH,
-	LD_LOADFLTR,
-	LD_LIBRARY_PATH_RPATH,
-	LD_PRELOAD_FDS,
-	LD_DYNAMIC_WEAK,
-	LD_TRACE_LOADED_OBJECTS,
-	LD_UTRACE,
-	LD_DUMP_REL_PRE,
-	LD_DUMP_REL_POST,
-	LD_TRACE_LOADED_OBJECTS_PROGNAME,
-	LD_TRACE_LOADED_OBJECTS_FMT1,
-	LD_TRACE_LOADED_OBJECTS_FMT2,
-	LD_TRACE_LOADED_OBJECTS_ALL,
-	LD_SHOW_AUXV,
-	LD_STATIC_TLS_EXTRA,
-};
-
 struct ld_env_var_desc {
 	const char * const n;
 	const char *val;
@@ -401,9 +375,10 @@
 	LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false),
 	LD_ENV_DESC(SHOW_AUXV, false),
 	LD_ENV_DESC(STATIC_TLS_EXTRA, false),
+	LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false),
 };
 
-static const char *
+const char *
 ld_get_env_var(int idx)
 {
 	return (ld_env_vars[idx].val);
diff --git a/libexec/rtld-elf/rtld_lock.c b/libexec/rtld-elf/rtld_lock.c
--- a/libexec/rtld-elf/rtld_lock.c
+++ b/libexec/rtld-elf/rtld_lock.c
@@ -463,6 +463,7 @@
 
 	if (locks == NULL)
 		return;
+	bzero(ls, sizeof(ls));
 
 	/*
 	 * Warning: this did not worked well with the rtld compat
@@ -472,7 +473,8 @@
 	 * _rtld_atfork_pre() must provide the working implementation
 	 * of the locks anyway, and libthr locks are fine.
 	 */
-	wlock_acquire(rtld_phdr_lock, &ls[0]);
+	if (ld_get_env_var(LD_NO_DL_ITERATE_PHDR_AFTER_FORK) == NULL)
+		wlock_acquire(rtld_phdr_lock, &ls[0]);
 	wlock_acquire(rtld_bind_lock, &ls[1]);
 
 	/* XXXKIB: I am really sorry for this. */
@@ -492,5 +494,6 @@
 	ls[0].lockstate = locks[2];
 	ls[1].lockstate = locks[0];
 	lock_release(rtld_bind_lock, &ls[1]);
-	lock_release(rtld_phdr_lock, &ls[0]);
+	if (ld_get_env_var(LD_NO_DL_ITERATE_PHDR_AFTER_FORK) == NULL)
+		lock_release(rtld_phdr_lock, &ls[0]);
 }