diff --git a/tests/testutils.c b/tests/testutils.c
index 87646736537fadfd0ce6a950eb0d654361220f87..4f17e5176fbcbf39b2a0dd2e19e510da2409f337 100644
--- a/tests/testutils.c
+++ b/tests/testutils.c
@@ -280,6 +280,12 @@ int virtTestCaptureProgramOutput(const char *const argv[],
         }
     }
 }
+#else /* !WIN32 */
+int virtTestCaptureProgramOutput(const char *const argv[] ATTRIBUTE_UNUSED,
+                                 char **buf ATTRIBUTE_UNUSED,
+                                 int buflen ATTRIBUTE_UNUSED) {
+    return -1;
+}
 #endif /* !WIN32 */