diff --git a/embedvar.h b/embedvar.h
index b70dd1745db1..df13032e0d12 100644
--- a/embedvar.h
+++ b/embedvar.h
@@ -106,6 +106,7 @@
 # define PL_efloatsize                          (vTHX->Iefloatsize)
 # define PL_endav                               (vTHX->Iendav)
 # define PL_Env                                 (vTHX->IEnv)
+# define PL_env_mutex_depth                     (vTHX->Ienv_mutex_depth)
 # define PL_envgv                               (vTHX->Ienvgv)
 # define PL_errgv                               (vTHX->Ierrgv)
 # define PL_errors                              (vTHX->Ierrors)
diff --git a/intrpvar.h b/intrpvar.h
index e17ce3fb5c56..d939023705af 100644
--- a/intrpvar.h
+++ b/intrpvar.h
@@ -902,6 +902,7 @@ PERLVAR(I, regex_padav,   AV *)		/* All regex objects, indexed via the
 PERLVAR(I, stashpad,    HV **)		/* for CopSTASH */
 PERLVARI(I, stashpadmax, PADOFFSET, 64)
 PERLVARI(I, stashpadix, PADOFFSET, 0)
+PERLVARI(I, env_mutex_depth, int, 0)     /* Emulate general semaphore */
 #endif
 
 #ifdef USE_REENTRANT_API
diff --git a/makedef.pl b/makedef.pl
index ea46299104c3..6a461956acad 100644
--- a/makedef.pl
+++ b/makedef.pl
@@ -417,7 +417,8 @@ sub readvar {
 		    PL_regex_padav
 		    PL_dollarzero_mutex
 		    PL_env_mutex
-		    PL_hints_mutex
+                    PL_env_mutex_depth
+                    PL_hints_mutex
 		    PL_locale_mutex
 		    PL_locale_mutex_depth
 		    PL_my_ctx_mutex
diff --git a/perl.h b/perl.h
index 64901c2eb550..7297fd86f88c 100644
--- a/perl.h
+++ b/perl.h
@@ -7065,8 +7065,13 @@ typedef struct am_table_short AMTS;
 #endif
 
 #ifdef USE_THREADS
-#  define ENV_LOCK            PERL_WRITE_LOCK(&PL_env_mutex)
-#  define ENV_UNLOCK          PERL_WRITE_UNLOCK(&PL_env_mutex)
+#  define ENV_LOCK            PERL_REENTRANT_LOCK("env",                    \
+                                                  &PL_env_mutex,            \
+                                                  PL_env_mutex_depth,       \
+                                                  1)
+#  define ENV_UNLOCK          PERL_REENTRANT_UNLOCK("env",                  \
+                                                    &PL_env_mutex,          \
+                                                    PL_env_mutex_depth)
 #  define ENV_READ_LOCK       PERL_READ_LOCK(&PL_env_mutex)
 #  define ENV_READ_UNLOCK     PERL_READ_UNLOCK(&PL_env_mutex)
 #  define ENV_INIT            PERL_RW_MUTEX_INIT(&PL_env_mutex)
diff --git a/sv.c b/sv.c
index b90721f810b0..d5ccc4e2381c 100644
--- a/sv.c
+++ b/sv.c
@@ -16240,6 +16240,10 @@ perl_clone_using(PerlInterpreter *proto_perl, UV flags,
     PL_less_dicey_locale_buf = NULL;
     PL_less_dicey_locale_bufsize = 0;
 #endif
+#ifdef USE_THREADS
+    assert(PL_env_mutex_depth <= 0);
+    PL_env_mutex_depth = 0;
+#endif
 
     /* Unicode inversion lists */