diff --git a/packages/core/src/lib/pseudopattern_hunter.js b/packages/core/src/lib/pseudopattern_hunter.js
index 42e241aca..e5dcaf781 100644
--- a/packages/core/src/lib/pseudopattern_hunter.js
+++ b/packages/core/src/lib/pseudopattern_hunter.js
@@ -67,9 +67,14 @@ pseudopattern_hunter.prototype.find_pseudopatterns = function(
         (objValue, srcValue) => {
           if (
             _.isArray(objValue) &&
+            // If the parameter is not available after updating pattern lab but
+            // not the patternlab-config it should not override arrays.
+            patternlab.config.hasOwnProperty('patternMergeVariantArrays') &&
             !patternlab.config.patternMergeVariantArrays
           ) {
             return srcValue;
+          } else if (_.isArray(objValue)) {
+            return objValue.concat(srcValue);
           }
           // Lodash will only check for "undefined" and eslint needs a consistent
           // return so do not remove
diff --git a/packages/core/test/files/_patterns/00-test/475-variant-test.json b/packages/core/test/files/_patterns/00-test/475-variant-test.json
new file mode 100644
index 000000000..9d371748a
--- /dev/null
+++ b/packages/core/test/files/_patterns/00-test/475-variant-test.json
@@ -0,0 +1,9 @@
+{
+    "a": 1,
+    "b": [2, 3],
+    "c": {
+        "d": [4, 5],
+        "e": 8,
+        "f": {"a": ["a"], "b": ["b"], "c": ["c"]}
+    }
+}
\ No newline at end of file
diff --git a/packages/core/test/files/_patterns/00-test/475-variant-test.mustache b/packages/core/test/files/_patterns/00-test/475-variant-test.mustache
new file mode 100644
index 000000000..fe4dd1f58
--- /dev/null
+++ b/packages/core/test/files/_patterns/00-test/475-variant-test.mustache
@@ -0,0 +1 @@
+{{a}}
\ No newline at end of file
diff --git a/packages/core/test/files/_patterns/00-test/475-variant-test~merge.json b/packages/core/test/files/_patterns/00-test/475-variant-test~merge.json
new file mode 100644
index 000000000..c60d0974c
--- /dev/null
+++ b/packages/core/test/files/_patterns/00-test/475-variant-test~merge.json
@@ -0,0 +1,8 @@
+{
+    "a": 2,
+    "b": [8],
+    "c": {
+        "d": [6, 7],
+        "f": {"b": ["x"]}
+    }
+}
\ No newline at end of file
diff --git a/packages/core/test/pseudopattern_hunter_tests.js b/packages/core/test/pseudopattern_hunter_tests.js
index 1464f28b4..fed26b16c 100644
--- a/packages/core/test/pseudopattern_hunter_tests.js
+++ b/packages/core/test/pseudopattern_hunter_tests.js
@@ -133,3 +133,72 @@ tap.test(
     });
   }
 );
+
+tap.test('pseudo pattern variant data should merge arrays', function(test) {
+  const pl = stubPatternlab();
+  pl.config.patternMergeVariantArrays = true;
+
+  const pattern = loadPattern('00-test/475-variant-test.mustache', pl);
+
+  addPattern(pattern, pl);
+
+  return pph.find_pseudopatterns(pattern, pl).then(() => {
+    test.equals(pl.patterns[1].patternPartial, 'test-variant-test-merge');
+    test.equals(
+      JSON.stringify(pl.patterns[1].jsonFileData),
+      JSON.stringify({
+        a: 2,
+        b: [2, 3, 8],
+        c: { d: [4, 5, 6, 7], e: 8, f: { a: ['a'], b: ['b', 'x'], c: ['c'] } },
+      })
+    );
+  });
+});
+
+tap.test(
+  'pseudo pattern variant data should merge arrays if config "patternMergeVariantArrays" is not available as default behavior',
+  function(test) {
+    const pl = stubPatternlab();
+
+    const pattern = loadPattern('00-test/475-variant-test.mustache', pl);
+
+    addPattern(pattern, pl);
+
+    return pph.find_pseudopatterns(pattern, pl).then(() => {
+      test.equals(pl.patterns[1].patternPartial, 'test-variant-test-merge');
+      test.equals(
+        JSON.stringify(pl.patterns[1].jsonFileData),
+        JSON.stringify({
+          a: 2,
+          b: [2, 3, 8],
+          c: {
+            d: [4, 5, 6, 7],
+            e: 8,
+            f: { a: ['a'], b: ['b', 'x'], c: ['c'] },
+          },
+        })
+      );
+    });
+  }
+);
+
+tap.test('pseudo pattern variant data should override arrays', function(test) {
+  const pl = stubPatternlab();
+  pl.config.patternMergeVariantArrays = false;
+
+  const pattern = loadPattern('00-test/475-variant-test.mustache', pl);
+
+  addPattern(pattern, pl);
+
+  return pph.find_pseudopatterns(pattern, pl).then(() => {
+    test.equals(pl.patterns[1].patternPartial, 'test-variant-test-merge');
+    test.equals(
+      JSON.stringify(pl.patterns[1].jsonFileData),
+      JSON.stringify({
+        a: 2,
+        b: [8],
+        c: { d: [6, 7], e: 8, f: { a: ['a'], b: ['x'], c: ['c'] } },
+      })
+    );
+  });
+});