diff --git a/promql/lex.go b/promql/lex.go
index 90f82f373..5d390ca11 100644
--- a/promql/lex.go
+++ b/promql/lex.go
@@ -163,11 +163,6 @@ const (
 	itemGroupLeft
 	itemGroupRight
 	itemBool
-	// Old alerting syntax
-	itemWith
-	itemSummary
-	itemRunbook
-	itemDescription
 	keywordsEnd
 )
 
@@ -200,12 +195,6 @@ var key = map[string]itemType{
 	"group_left":    itemGroupLeft,
 	"group_right":   itemGroupRight,
 	"bool":          itemBool,
-
-	// Old alerting syntax.
-	"with":        itemWith,
-	"summary":     itemSummary,
-	"runbook":     itemRunbook,
-	"description": itemDescription,
 }
 
 // These are the default string representations for common items. It does not
diff --git a/promql/lex_test.go b/promql/lex_test.go
index 9ff8e4420..d516c3d93 100644
--- a/promql/lex_test.go
+++ b/promql/lex_test.go
@@ -263,18 +263,6 @@ var tests = []struct {
 	}, {
 		input:    "annotations",
 		expected: []item{{itemAnnotations, 0, "annotations"}},
-	}, {
-		input:    "description",
-		expected: []item{{itemDescription, 0, "description"}},
-	}, {
-		input:    "summary",
-		expected: []item{{itemSummary, 0, "summary"}},
-	}, {
-		input:    "runbook",
-		expected: []item{{itemRunbook, 0, "runbook"}},
-	}, {
-		input:    "with",
-		expected: []item{{itemWith, 0, "with"}},
 	}, {
 		input:    "offset",
 		expected: []item{{itemOffset, 0, "offset"}},
diff --git a/promql/parse.go b/promql/parse.go
index 758d87922..c91df6fb3 100644
--- a/promql/parse.go
+++ b/promql/parse.go
@@ -384,57 +384,17 @@ func (p *parser) alertStmt() *AlertStmt {
 		}
 	}
 
-	// Accepting WITH instead of LABELS is temporary compatibility
-	// with the old alerting syntax.
 	var (
-		hasLabels   bool
-		oldSyntax   bool
 		labels      = model.LabelSet{}
 		annotations = model.LabelSet{}
 	)
-	if t := p.peek().typ; t == itemLabels {
+	if p.peek().typ == itemLabels {
 		p.expect(itemLabels, ctx)
 		labels = p.labelSet()
-		hasLabels = true
-	} else if t == itemWith {
-		p.expect(itemWith, ctx)
-		labels = p.labelSet()
-		oldSyntax = true
 	}
-
-	// Only allow old annotation syntax if new label syntax isn't used.
-	if !hasLabels {
-	Loop:
-		for {
-			switch p.next().typ {
-			case itemSummary:
-				annotations["summary"] = model.LabelValue(p.unquoteString(p.expect(itemString, ctx).val))
-
-			case itemDescription:
-				annotations["description"] = model.LabelValue(p.unquoteString(p.expect(itemString, ctx).val))
-
-			case itemRunbook:
-				annotations["runbook"] = model.LabelValue(p.unquoteString(p.expect(itemString, ctx).val))
-
-			default:
-				p.backup()
-				break Loop
-			}
-		}
-		if len(annotations) > 0 {
-			oldSyntax = true
-		}
-	}
-
-	// Only allow new annotation syntax if WITH or old annotation
-	// syntax weren't used.
-	if !oldSyntax {
-		if p.peek().typ == itemAnnotations {
-			p.expect(itemAnnotations, ctx)
-			annotations = p.labelSet()
-		}
-	} else {
-		log.Warnf("Alerting rule with old syntax found. Support for this syntax will be removed with 0.18. Please update to the new syntax.")
+	if p.peek().typ == itemAnnotations {
+		p.expect(itemAnnotations, ctx)
+		annotations = p.labelSet()
 	}
 
 	return &AlertStmt{
diff --git a/promql/parse_test.go b/promql/parse_test.go
index 28a12a677..b438d2ec8 100644
--- a/promql/parse_test.go
+++ b/promql/parse_test.go
@@ -1311,32 +1311,6 @@ var testStatement = []struct {
 				Labels: model.LabelSet{"x": "", "a": "z"},
 			},
 		},
-	}, {
-		input: `ALERT SomeName IF some_metric > 1
-			WITH {}
-			SUMMARY "Global request rate low"
-			DESCRIPTION "The global request rate is low"
-		`,
-		expected: Statements{
-			&AlertStmt{
-				Name: "SomeName",
-				Expr: &BinaryExpr{
-					Op: itemGTR,
-					LHS: &VectorSelector{
-						Name: "some_metric",
-						LabelMatchers: metric.LabelMatchers{
-							{Type: metric.Equal, Name: model.MetricNameLabel, Value: "some_metric"},
-						},
-					},
-					RHS: &NumberLiteral{1},
-				},
-				Labels: model.LabelSet{},
-				Annotations: model.LabelSet{
-					"summary":     "Global request rate low",
-					"description": "The global request rate is low",
-				},
-			},
-		},
 	}, {
 		input: `ALERT SomeName IF some_metric > 1
 			LABELS {}