diff --git a/VersionedMap.cpp b/VersionedMap.cpp
index 7481717..929de54 100644
--- a/VersionedMap.cpp
+++ b/VersionedMap.cpp
@@ -1325,13 +1325,21 @@ int64_t VersionedMap::getBytes() const { return impl->getBytes(); }
 
 // GCOVR_EXCL_START
 
-void VersionedMap::Impl::printInOrder(int64_t version) {
+#ifdef NDEBUG
+inline
+#endif
+    void
+    VersionedMap::Impl::printInOrder(int64_t version) {
   printInOrderHelper(version,
                      roots.getThreadSafeHandle().rootForVersion(version), 0);
 }
 
-void VersionedMap::Impl::printInOrderHelper(int64_t version, uint32_t node,
-                                            int depth) {
+#ifdef NDEBUG
+inline
+#endif
+    void
+    VersionedMap::Impl::printInOrderHelper(int64_t version, uint32_t node,
+                                           int depth) {
   if (node == 0) {
     return;
   }