diff --git a/changelog.md b/changelog.md
index fc7257ee5..ded894706 100755
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+## Next
+
+## Bug fixes
+
+- [jss] Fix SSR aggregation regression ([#1064](https://github.com/cssinjs/jss/pull/1064))
+
 ## 10.0.0-alpha.13 (2019-3-12)
 
 ### Bug fixes
diff --git a/packages/jss/.size-snapshot.json b/packages/jss/.size-snapshot.json
index da842e7f9..0424e2707 100644
--- a/packages/jss/.size-snapshot.json
+++ b/packages/jss/.size-snapshot.json
@@ -1,30 +1,30 @@
 {
   "dist/jss.js": {
-    "bundled": 58916,
-    "minified": 21875,
-    "gzipped": 6588
+    "bundled": 58897,
+    "minified": 21872,
+    "gzipped": 6582
   },
   "dist/jss.min.js": {
-    "bundled": 57750,
-    "minified": 20957,
-    "gzipped": 6146
+    "bundled": 57731,
+    "minified": 20954,
+    "gzipped": 6139
   },
   "dist/jss.cjs.js": {
-    "bundled": 54372,
-    "minified": 23786,
-    "gzipped": 6638
+    "bundled": 54357,
+    "minified": 23783,
+    "gzipped": 6633
   },
   "dist/jss.esm.js": {
-    "bundled": 53876,
-    "minified": 23382,
-    "gzipped": 6555,
+    "bundled": 53861,
+    "minified": 23379,
+    "gzipped": 6550,
     "treeshaked": {
       "rollup": {
-        "code": 19017,
+        "code": 19014,
         "import_statements": 281
       },
       "webpack": {
-        "code": 20432
+        "code": 20429
       }
     }
   }
diff --git a/packages/jss/src/StyleSheet.js b/packages/jss/src/StyleSheet.js
index 27b886795..319e566ff 100644
--- a/packages/jss/src/StyleSheet.js
+++ b/packages/jss/src/StyleSheet.js
@@ -59,8 +59,8 @@ export default class StyleSheet {
    * Attach renderable to the render tree.
    */
   attach(): this {
-    if (this.attached || !this.renderer) return this
-    this.renderer.attach()
+    if (this.attached) return this
+    if (this.renderer) this.renderer.attach()
     this.attached = true
     // Order is important, because we can't use insertRule API if style element is not attached.
     if (!this.deployed) this.deploy()
@@ -71,8 +71,8 @@ export default class StyleSheet {
    * Remove renderable from render tree.
    */
   detach(): this {
-    if (!this.attached || !this.renderer) return this
-    this.renderer.detach()
+    if (!this.attached) return this
+    if (this.renderer) this.renderer.detach()
     this.attached = false
     return this
   }
@@ -175,10 +175,8 @@ export default class StyleSheet {
    * Deploy pure CSS string to a renderable.
    */
   deploy(): this {
-    if (this.renderer) {
-      this.renderer.deploy()
-      this.deployed = true
-    }
+    if (this.renderer) this.renderer.deploy()
+    this.deployed = true
     return this
   }
 
diff --git a/packages/react-jss/src/JssProvider.test.js b/packages/react-jss/src/JssProvider.test.js
index 0a60c2971..dcb7c28a8 100644
--- a/packages/react-jss/src/JssProvider.test.js
+++ b/packages/react-jss/src/JssProvider.test.js
@@ -5,6 +5,7 @@ import React from 'react'
 import {stripIndent} from 'common-tags'
 import {create} from 'jss'
 import TestRenderer from 'react-test-renderer'
+import preset from 'jss-preset-default'
 
 import withStyles, {SheetsRegistry, JssProvider} from '.'
 
@@ -249,9 +250,11 @@ describe('React-JSS: JssProvider', () => {
       }
       const MyComponent = withStyles(styles)()
       let generateId = createGenerateId()
+      // Remove renderer to simulate a non-browser env.
+      const jss = create({...preset(), Renderer: null})
 
       TestRenderer.create(
-        <JssProvider registry={registry} generateId={generateId}>
+        <JssProvider registry={registry} generateId={generateId} jss={jss}>
           <MyComponent border="green" />
         </JssProvider>
       )
@@ -269,7 +272,7 @@ describe('React-JSS: JssProvider', () => {
       generateId = createGenerateId()
 
       TestRenderer.create(
-        <JssProvider registry={registry} generateId={generateId}>
+        <JssProvider registry={registry} generateId={generateId} jss={jss}>
           <MyComponent border="blue" />
         </JssProvider>
       )
@@ -295,15 +298,17 @@ describe('React-JSS: JssProvider', () => {
       const customSheets2 = new SheetsRegistry()
       const generateId1 = createGenerateId()
       const generateId2 = createGenerateId()
+      // Remove renderer to simulate a non-browser env.
+      const jss = create({...preset(), Renderer: null})
 
       TestRenderer.create(
-        <JssProvider registry={customSheets1} generateId={generateId1}>
+        <JssProvider registry={customSheets1} generateId={generateId1} jss={jss}>
           <MyComponent color="#000" />
         </JssProvider>
       )
 
       TestRenderer.create(
-        <JssProvider registry={customSheets2} generateId={generateId2}>
+        <JssProvider registry={customSheets2} generateId={generateId2} jss={jss}>
           <MyComponent color="#000" />
         </JssProvider>
       )
@@ -312,6 +317,7 @@ describe('React-JSS: JssProvider', () => {
       const result2 = customSheets2.toString()
 
       expect(result1).to.equal(result2)
+      expect(result1.length > 0).to.be(true)
     })
   })
 })