diff --git a/TSRM/TSRM.c b/TSRM/TSRM.c
index 22dd54ce6ef..dc0ecff44ed 100644
--- a/TSRM/TSRM.c
+++ b/TSRM/TSRM.c
@@ -736,13 +736,13 @@ TSRM_API size_t tsrm_get_ls_cache_tcb_offset(void)
 #if defined(__APPLE__) && defined(__x86_64__)
     // TODO: Implement support for fast JIT ZTS code ???
 	return 0;
-#elif defined(__x86_64__) && defined(__GNUC__) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
+#elif defined(__x86_64__) && defined(__GNUC__) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__MUSL__)
 	size_t ret;
 
 	asm ("movq _tsrm_ls_cache@gottpoff(%%rip),%0"
           : "=r" (ret));
 	return ret;
-#elif defined(__i386__) && defined(__GNUC__) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
+#elif defined(__i386__) && defined(__GNUC__) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__MUSL__)
 	size_t ret;
 
 	asm ("leal _tsrm_ls_cache@ntpoff,%0"
diff --git a/configure.ac b/configure.ac
index f89b9fa42bc..c2886439afa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -260,7 +260,7 @@ AC_MSG_CHECKING([whether we are using musl libc])
 if command -v ldd >/dev/null && ldd --version 2>&1 | grep -q ^musl
 then
   AC_MSG_RESULT(yes)
-  CPPFLAGS="$CPPFLAGS -D__MUSL__"
+  AC_DEFINE([__MUSL__], [1], [Define when using musl libc])
 else
   AC_MSG_RESULT(no)
 fi
diff --git a/ext/opcache/jit/zend_jit_x86.dasc b/ext/opcache/jit/zend_jit_x86.dasc
index dc35eade06e..dfb136bceec 100644
--- a/ext/opcache/jit/zend_jit_x86.dasc
+++ b/ext/opcache/jit/zend_jit_x86.dasc
@@ -2956,7 +2956,7 @@ static int zend_jit_setup(void)
 # elif defined(__GNUC__) && defined(__x86_64__)
 	tsrm_ls_cache_tcb_offset = tsrm_get_ls_cache_tcb_offset();
 	if (tsrm_ls_cache_tcb_offset == 0) {
-#if defined(__has_attribute) && __has_attribute(tls_model) && !defined(__FreeBSD__) && !defined(__OpenBSD__)
+#if defined(__has_attribute) && __has_attribute(tls_model) && !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__MUSL__)
 		size_t ret;
 
 		asm ("movq _tsrm_ls_cache@gottpoff(%%rip),%0"
@@ -2975,7 +2975,7 @@ static int zend_jit_setup(void)
 # elif defined(__GNUC__) && defined(__i386__)
 	tsrm_ls_cache_tcb_offset = tsrm_get_ls_cache_tcb_offset();
 	if (tsrm_ls_cache_tcb_offset == 0) {
-#if !defined(__FreeBSD__) && !defined(__OpenBSD__)
+#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__MUSL__)
 		size_t ret;
 
 		asm ("leal _tsrm_ls_cache@ntpoff,%0\n"