diff --git a/src/util/virhostcpu.h b/src/util/virhostcpu.h
index 11cbcd72a3..6148f9e66f 100644
--- a/src/util/virhostcpu.h
+++ b/src/util/virhostcpu.h
@@ -75,7 +75,8 @@ virBitmapPtr virHostCPUGetSiblingsList(unsigned int cpu);
 
 int virHostCPUGetOnline(unsigned int cpu, bool *online);
 
-unsigned int virHostCPUGetMicrocodeVersion(virArch hostArch);
+unsigned int
+virHostCPUGetMicrocodeVersion(virArch hostArch) G_GNUC_NO_INLINE;
 
 int virHostCPUGetMSR(unsigned long index,
                      uint64_t *msr);
diff --git a/tests/domaincapsmock.c b/tests/domaincapsmock.c
index 90e17c19f0..d81a898dc0 100644
--- a/tests/domaincapsmock.c
+++ b/tests/domaincapsmock.c
@@ -34,3 +34,9 @@ virHostCPUGetKVMMaxVCPUs(void)
 {
     return INT_MAX;
 }
+
+unsigned int
+virHostCPUGetMicrocodeVersion(virArch hostArch G_GNUC_UNUSED)
+{
+    return 0;
+}