diff --git a/debian/patches/series b/debian/patches/series
index 3748d9690..cf2975925 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -59,6 +59,7 @@ upstream/limit_the_execution_of_dialplan_reload.patch
 upstream/tm-execute-TMCB_REQUEST_FWDED-cb-as-BRANCH_ROUTE-whe.patch
 upstream/cfgt-don-t-try-to-create-dir-if-it-already-exists.patch
 upstream/cfgt-fix-detection-of-jump-to-previous-previous-rout.patch
+upstream/Makefile.defs-use-dedicated-vars-for-pthread-mutex-f.patch
 ## backport from kamailio trunk (5.4)
 upstream/cfgt-group-RPC-commands-using-module-name.patch
 upstream/cfgt-add-docs-for-missing-RPC-commands.patch
diff --git a/debian/patches/upstream/Makefile.defs-use-dedicated-vars-for-pthread-mutex-f.patch b/debian/patches/upstream/Makefile.defs-use-dedicated-vars-for-pthread-mutex-f.patch
new file mode 100644
index 000000000..5edb11a5d
--- /dev/null
+++ b/debian/patches/upstream/Makefile.defs-use-dedicated-vars-for-pthread-mutex-f.patch
@@ -0,0 +1,65 @@
+From 354cce84135836a780364f1fef441ba850c9f2ff Mon Sep 17 00:00:00 2001
+From: Daniel-Constantin Mierla <miconda@gmail.com>
+Date: Tue, 17 Dec 2019 07:49:57 +0100
+Subject: [PATCH] Makefile.defs: use dedicated vars for pthread mutex flags
+
+- CC_EXTRA_OPTS and LD_EXTRA_OPTS may be set from environment
+
+(cherry picked from commit be34082aac3e275058f4747c3706499848ccd86d)
+---
+ src/Makefile.defs | 18 +++++++++++-------
+ 1 file changed, 11 insertions(+), 7 deletions(-)
+
+diff --git a/src/Makefile.defs b/src/Makefile.defs
+index 483a11eb2..a3a07a89d 100644
+--- a/src/Makefile.defs
++++ b/src/Makefile.defs
+@@ -210,8 +210,11 @@ endif
+ endif
+ 
+ ifeq ($(LIBSSL_SET_MUTEX_SHARED), 1)
+-CC_EXTRA_OPTS+= -pthread -DKSR_PTHREAD_MUTEX_SHARED
+-LD_EXTRA_OPTS+= -pthread -rdynamic -ldl -Wl,-Bsymbolic-functions
++CC_PMUTEX_OPTS = -pthread -DKSR_PTHREAD_MUTEX_SHARED
++LD_PMUTEX_OPTS = -pthread -rdynamic -ldl -Wl,-Bsymbolic-functions
++else
++CC_PMUTEX_OPTS =
++LD_PMUTEX_OPTS =
+ endif
+ 
+ ifeq ($(OS), solaris)
+@@ -1630,7 +1633,7 @@ $(error 			Unsupported compiler ($(CC):$(CC_NAME)), try gcc)
+ endif		#CC_NAME, gcc
+ endif	#ARCH, ppc
+ 
+-CFLAGS+= $(CC_EXTRA_OPTS)
++CFLAGS+= $(CC_EXTRA_OPTS) $(CC_PMUTEX_OPTS)
+ 
+ 
+ # setting LDFLAGS
+@@ -1679,9 +1682,9 @@ ifeq ($(CC_NAME), clang)
+ 	LD_RPATH=-Wl,-rpath,
+ endif
+ 
+-LDFLAGS+= $(LD_EXTRA_OPTS)
+-MOD_LDFLAGS+= $(LD_EXTRA_OPTS)
+-LIB_LDFLAGS+= $(LD_EXTRA_OPTS)
++LDFLAGS+= $(LD_EXTRA_OPTS) $(LD_PMUTEX_OPTS)
++MOD_LDFLAGS+= $(LD_EXTRA_OPTS) $(LD_PMUTEX_OPTS)
++LIB_LDFLAGS+= $(LD_EXTRA_OPTS) $(LD_PMUTEX_OPTS)
+ 
+ else	#mode,release
+ ifeq	($(CC_NAME), gcc)
+@@ -2125,7 +2128,8 @@ saved_fixed_vars:=	MAIN_NAME  CFG_NAME SCR_NAME FLAVOUR INSTALL_FLAVOUR \
+ # variable changeable at compile time
+ # extra: prefix DESTDIR BASEDIR basedirt
+ saved_chg_vars:=\
+-		CC_EXTRA_OPTS CPUTYPE CFLAGS_RM CFLAGS MOD_CFLAGS LIB_CFLAGS UTILS_CFLAGS \
++		CC_EXTRA_OPTS CC_PMUTEX_OPTS CPUTYPE CFLAGS_RM CFLAGS MOD_CFLAGS \
++		LIB_CFLAGS UTILS_CFLAGS \
+ 		BASEDIR basedir DESTDIR LIBDIR RUNBASEDIR runbasedir \
+ 		PREFIX prefix \
+ 		cfg_prefix cfg_dir bin_prefix bin_dir modules_prefix modules_dir \
+-- 
+2.20.1
+