diff --git a/src/jsifier.js b/src/jsifier.js
index f8fa0e0f7..3f41c1792 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -520,7 +520,7 @@ function JSify(data, functionsOnly, givenFunctions) {
           var type = removePointing(param.type);
           var typeInfo = Types.types[type];
           func.JS += '  var tempParam = ' + param.ident + '; ' + param.ident + ' = ' + RuntimeGenerator.stackAlloc(typeInfo.flatSize) + ';' +
-                     makeCopyValues(param.ident, 'tempParam', typeInfo.flatSize, 'null', null, 1) + ';\n';
+                     makeCopyValues(param.ident, 'tempParam', typeInfo.flatSize, 'null', null, param.byVal) + ';\n';
         }
       });
 
diff --git a/src/parseTools.js b/src/parseTools.js
index 3a88fc255..0601045d4 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -314,12 +314,14 @@ function parseParamTokens(params) {
     var segment = params.slice(0, i);
     params = params.slice(i+1);
     segment = cleanSegment(segment);
-    var byVal = false;
+    var byVal = 0;
     if (segment[1] && segment[1].text === 'byval') {
-      // handle 'byval' and 'byval align X'
-      byVal = true;
+      // handle 'byval' and 'byval align X'. We store the alignment in 'byVal'
+      byVal = QUANTUM_SIZE;
       segment.splice(1, 1);
       if (segment[1] && segment[1].text === 'align') {
+        assert(isNumber(segment[2].text));
+        byVal = parseInt(segment[2].text);
         segment.splice(1, 2);
       }
     }