diff --git a/spa/include/spa/pod/parser.h b/spa/include/spa/pod/parser.h
index e01bf91aa..909431e1c 100644
--- a/spa/include/spa/pod/parser.h
+++ b/spa/include/spa/pod/parser.h
@@ -90,7 +90,12 @@ spa_pod_parser_read_header(struct spa_pod_parser *parser, uint32_t offset, uint3
 	/* Cast to uint64_t to avoid wraparound. */
 	const uint64_t long_offset = (uint64_t)offset + header_size;
 	if (long_offset <= size && (offset & 7) == 0) {
+		/* a barrier around the memcpy to make sure it is not moved around or
+		 * duplicated after the size check below. We need to to work on shared
+		 * memory while there could be updates happening while we read. */
+		SPA_BARRIER;
 		memcpy(header, SPA_PTROFF(parser->data, offset, void), header_size);
+		SPA_BARRIER;
 		struct spa_pod *pod = SPA_PTROFF(header, pod_offset, struct spa_pod);
 		/* Check that the size (rounded to the next multiple of 8) is in bounds. */
 		if (long_offset + SPA_ROUND_UP_N((uint64_t)pod->size, SPA_POD_ALIGN) <= size) {
diff --git a/spa/include/spa/utils/defs.h b/spa/include/spa/utils/defs.h
index 55bf9ad97..371b1e658 100644
--- a/spa/include/spa/utils/defs.h
+++ b/spa/include/spa/utils/defs.h
@@ -242,6 +242,7 @@ struct spa_fraction {
 #define SPA_UNUSED __attribute__ ((unused))
 #define SPA_NORETURN __attribute__ ((noreturn))
 #define SPA_WARN_UNUSED_RESULT __attribute__ ((warn_unused_result))
+#define SPA_BARRIER __asm__ __volatile__("": : :"memory")
 #else
 #define SPA_PRINTF_FUNC(fmt, arg1)
 #define SPA_FORMAT_ARG_FUNC(arg1)
@@ -252,6 +253,7 @@ struct spa_fraction {
 #define SPA_UNUSED
 #define SPA_NORETURN
 #define SPA_WARN_UNUSED_RESULT
+#define SPA_BARRIER
 #endif
 
 #ifndef SPA_API_IMPL