diff --git a/src/core/pattern.js b/src/core/pattern.js
index eead24862..42d4b236f 100644
--- a/src/core/pattern.js
+++ b/src/core/pattern.js
@@ -225,7 +225,7 @@ Shadings.Mesh = (function MeshClosure() {
 
     var numComps = context.numComps;
     this.tmpCompsBuf = new Float32Array(numComps);
-    var csNumComps = context.colorSpace;
+    var csNumComps = context.colorSpace.numComps;
     this.tmpCsCompsBuf = context.colorFn ? new Float32Array(csNumComps) :
                                            this.tmpCompsBuf;
   }
diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
index 3e6cf42a7..ba8c87bf3 100644
--- a/test/pdfs/.gitignore
+++ b/test/pdfs/.gitignore
@@ -23,6 +23,7 @@
 !sizes.pdf
 !close-path-bug.pdf
 !issue2948.pdf
+!issue6231_1.pdf
 !issue4630.pdf
 !issue4909.pdf
 !issue5202.pdf
diff --git a/test/pdfs/issue6231_1.pdf b/test/pdfs/issue6231_1.pdf
new file mode 100644
index 000000000..59e9123a8
Binary files /dev/null and b/test/pdfs/issue6231_1.pdf differ
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 5269624a1..ddda2d452 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -641,6 +641,13 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "issue6231_1",
+       "file": "pdfs/issue6231_1.pdf",
+       "md5": "eb13a9366a5142833a858472c68b4749",
+       "link": false,
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "usmanm-bad-auto-fetch",
        "file": "pdfs/usmanm-bad.pdf",
        "md5": "38afb822433aaf07fc8f54807cd4f61a",