diff --git a/packages/babylon/src/plugins/flow.js b/packages/babylon/src/plugins/flow.js
index 06af0a4838..b4630f67b4 100644
--- a/packages/babylon/src/plugins/flow.js
+++ b/packages/babylon/src/plugins/flow.js
@@ -164,7 +164,7 @@ pp.flowParseTypeParameterDeclaration = function () {
 
   this.expectRelational("<");
   while (!this.isRelational(">")) {
-    node.params.push(this.parseFlowTypeParam());
+    node.params.push(this.flowParseExistentialTypeParam() || this.flowParseTypeAnnotatableIdentifier());
     if (!this.isRelational(">")) {
       this.expect(tt.comma);
     }
@@ -174,13 +174,11 @@ pp.flowParseTypeParameterDeclaration = function () {
   return this.finishNode(node, "TypeParameterDeclaration");
 };
 
-pp.parseFlowTypeParam = function () {
+pp.flowParseExistentialTypeParam = function () {
   if (this.match(tt.star)) {
     let node = this.startNode();
     this.next();
     return this.finishNode(node, "ExistentialTypeParam");
-  } else {
-    return this.flowParseTypeAnnotatableIdentifier();
   }
 };
 
@@ -192,7 +190,7 @@ pp.flowParseTypeParameterInstantiation = function () {
 
   this.expectRelational("<");
   while (!this.isRelational(">")) {
-    node.params.push(this.parseFlowTypeParam());
+    node.params.push(this.flowParseExistentialTypeParam() || this.flowParseType());
     if (!this.isRelational(">")) {
       this.expect(tt.comma);
     }
diff --git a/packages/babylon/test/fixtures/flow/type-annotations/existential-type-param/expected.json b/packages/babylon/test/fixtures/flow/type-annotations/existential-type-param/expected.json
index a412ffa9a8..c67f730713 100644
--- a/packages/babylon/test/fixtures/flow/type-annotations/existential-type-param/expected.json
+++ b/packages/babylon/test/fixtures/flow/type-annotations/existential-type-param/expected.json
@@ -121,7 +121,7 @@
             },
             "params": [
               {
-                "type": "Identifier",
+                "type": "GenericTypeAnnotation",
                 "start": 23,
                 "end": 24,
                 "loc": {
@@ -134,7 +134,23 @@
                     "column": 24
                   }
                 },
-                "name": "T"
+                "typeParameters": null,
+                "id": {
+                  "type": "Identifier",
+                  "start": 23,
+                  "end": 24,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 23
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 24
+                    }
+                  },
+                  "name": "T"
+                }
               },
               {
                 "type": "ExistentialTypeParam",