diff --git a/src/util/virbuffer.c b/src/util/virbuffer.c
index bcf9042573cc995464f813c5994d6fda5c7685bc..9a74ca78bb7a120a5e410f7da4140cd36ce5830b 100644
--- a/src/util/virbuffer.c
+++ b/src/util/virbuffer.c
@@ -784,8 +784,6 @@ virBufferStrcat(virBufferPtr buf, ...)
  * if the current tail of the buffer matches @str; a non-negative @len
  * further limits how much of the tail is trimmed.  If @str is NULL, then
  * @len must be non-negative.
- *
- * Sets error to -1 (usage) if str is NULL and len is less than zero.
  */
 void
 virBufferTrim(virBufferPtr buf, const char *str, int len)
@@ -794,10 +792,8 @@ virBufferTrim(virBufferPtr buf, const char *str, int len)
 
     if (!buf || buf->error)
         return;
-    if (!str && len < 0) {
-        virBufferSetError(buf, -1);
+    if (!str && len < 0)
         return;
-    }
 
     if (len > 0 && len > buf->use)
         return;
diff --git a/tests/virbuftest.c b/tests/virbuftest.c
index 385f016174ac066ac6945aafd9340bbc6c4204ea..8b8754adfa9f700feaece8df0b6ddc99240ae213 100644
--- a/tests/virbuftest.c
+++ b/tests/virbuftest.c
@@ -163,6 +163,7 @@ static int testBufTrim(const void *data G_GNUC_UNUSED)
     virBufferTrim(buf, "a", 2);
 
     virBufferAddLit(buf, ",b,,");
+    virBufferTrim(buf, NULL, -1);
     virBufferTrim(buf, "b", -1);
     virBufferTrim(buf, "b,,", 1);
     virBufferTrim(buf, ",", -1);
@@ -178,12 +179,6 @@ static int testBufTrim(const void *data G_GNUC_UNUSED)
         goto cleanup;
     }
 
-    virBufferTrim(buf, NULL, -1);
-    if (virBufferError(buf) != -1) {
-        VIR_TEST_DEBUG("Usage error not flagged");
-        goto cleanup;
-    }
-
     ret = 0;
 
  cleanup: