diff --git a/src/util/virbuffer.c b/src/util/virbuffer.c
index 693e4b2942ea6097fc77acda922481cbca799882..4969497c008b83cd4421e6842b0714618d4f8091 100644
--- a/src/util/virbuffer.c
+++ b/src/util/virbuffer.c
@@ -660,27 +660,28 @@ virBufferStrcat(virBufferPtr buf, ...)
  * further limits how much of the tail is trimmed.  If @str is NULL, then
  * @len must be non-negative.
  *
- * Returns -1 if @buf has previously encountered an error or if @len is
- * invalid, 0 if there was nothing to trim (@buf was too short or @str
- * didn't match), and 1 if the trim was successful.
+ * Sets error to -1 (usage) if str is NULL and len is less than zero.
  */
-int
+void
 virBufferTrim(virBufferPtr buf, const char *str, int len)
 {
     size_t len2 = 0;
 
-    if (!buf || buf->error || (!str && len < 0))
-        return -1;
+    if (!buf || buf->error)
+        return;
+    if (!str && len < 0) {
+        virBufferSetError(buf, -1);
+        return;
+    }
 
     if (len > 0 && len > buf->use)
-        return 0;
+        return;
     if (str) {
         len2 = strlen(str);
         if (len2 > buf->use ||
             memcmp(&buf->content[buf->use - len2], str, len2) != 0)
-            return 0;
+            return;
     }
     buf->use -= len < 0 ? len2 : len;
     buf->content[buf->use] = '\0';
-    return 1;
 }
diff --git a/src/util/virbuffer.h b/src/util/virbuffer.h
index 7b69c0e5cf0d1a3f36d7395faf525ac48db72d6a..e0b77ab7dde605f3f96d525f1daf4089629840af 100644
--- a/src/util/virbuffer.h
+++ b/src/util/virbuffer.h
@@ -77,6 +77,6 @@ void virBufferURIEncodeString(virBufferPtr buf, const char *str);
 void virBufferAdjustIndent(virBufferPtr buf, int indent);
 int virBufferGetIndent(const virBufferPtr buf, bool dynamic);
 
-int virBufferTrim(virBufferPtr buf, const char *trim, int len);
+void virBufferTrim(virBufferPtr buf, const char *trim, int len);
 
 #endif /* __VIR_BUFFER_H__ */
diff --git a/tests/virbuftest.c b/tests/virbuftest.c
index c7a504b2f1f42d5383d07af3e3dd020e07882eb1..3938f0df57bfbc3187dc69addb17804aaf3b893d 100644
--- a/tests/virbuftest.c
+++ b/tests/virbuftest.c
@@ -148,38 +148,21 @@ static int testBufTrim(const void *data ATTRIBUTE_UNUSED)
     char *result = NULL;
     const char *expected = "a,b";
     int ret = -1;
-    int i = 1;
-
-#define ACT(str, len, result) \
-    do {                                          \
-        if (virBufferTrim(buf, str, len) != result) {   \
-            TEST_ERROR("trim %d failed", i);            \
-            goto cleanup;                               \
-        }                                               \
-        i++;                                            \
-    } while (0);
-
-    if (virBufferTrim(buf, "", 0) != -1) {
-        TEST_ERROR("Wrong failure detection 1");
-        goto cleanup;
-    }
+
+    virBufferTrim(buf, "", 0);
     buf = &bufinit;
-    if (virBufferTrim(buf, NULL, -1) != -1) {
-        TEST_ERROR("Wrong failure detection 2");
-        goto cleanup;
-    }
 
     virBufferAddLit(buf, "a;");
-    ACT("", 0, 1);
-    ACT("", -1, 1);
-    ACT(NULL, 1, 1);
-    ACT(NULL, 5, 0);
-    ACT("a", 2, 0);
+    virBufferTrim(buf, "", 0);
+    virBufferTrim(buf, "", -1);
+    virBufferTrim(buf, NULL, 1);
+    virBufferTrim(buf, NULL, 5);
+    virBufferTrim(buf, "a", 2);
 
     virBufferAddLit(buf, ",b,,");
-    ACT("b", -1, 0);
-    ACT("b,,", 1, 1);
-    ACT(",", -1, 1);
+    virBufferTrim(buf, "b", -1);
+    virBufferTrim(buf, "b,,", 1);
+    virBufferTrim(buf, ",", -1);
 
     result = virBufferContentAndReset(buf);
     if (!result || STRNEQ(result, expected)) {
@@ -187,6 +170,12 @@ static int testBufTrim(const void *data ATTRIBUTE_UNUSED)
         goto cleanup;
     }
 
+    virBufferTrim(buf, NULL, -1);
+    if (virBufferError(buf) != -1) {
+        TEST_ERROR("Usage error not flagged");
+        goto cleanup;
+    }
+
     ret = 0;
 
 cleanup:
diff --git a/tools/virsh.c b/tools/virsh.c
index 26d37c69ad808e821e34484421aab99108202c45..af2bb76a8373172b7c86307091ffc13670080089 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -632,18 +632,15 @@ vshTreePrintInternal(vshControl *ctl,
                                  false, indent) < 0)
             goto cleanup;
     }
-    if (virBufferTrim(indent, "  ", -1) < 0)
-        goto cleanup;
+    virBufferTrim(indent, "  ", -1);
 
     /* If there was no child device, and we're the last in
      * a list of devices, then print another blank line */
     if (nextlastdev == -1 && devid == lastdev)
         vshPrint(ctl, "%s\n", virBufferCurrentContent(indent));
 
-    if (!root) {
-        if (virBufferTrim(indent, NULL, 2) < 0)
-            goto cleanup;
-    }
+    if (!root)
+        virBufferTrim(indent, NULL, 2);
     ret = 0;
 cleanup:
     return ret;