diff --git a/lib/less/parser/parser.js b/lib/less/parser/parser.js
index 0a5f14ad..83346b3c 100644
--- a/lib/less/parser/parser.js
+++ b/lib/less/parser/parser.js
@@ -932,7 +932,7 @@ var Parser = function Parser(context, imports, fileInfo) {
                         returner = { args:null, variadic: false },
                         expressions = [], argsSemiColon = [], argsComma = [],
                         isSemiColonSeparated, expressionContainsNamed, name, nameLoop,
-                        value, arg, expand;
+                        value, arg, expand, hasSep = true; 
 
                     parserInput.save();
 
@@ -953,7 +953,7 @@ var Parser = function Parser(context, imports, fileInfo) {
                             arg = entities.variable() || entities.property() || entities.literal() || entities.keyword() || this.call(true);
                         }
 
-                        if (!arg) {
+                        if (!arg || !hasSep) {
                             break;
                         }
 
@@ -1019,10 +1019,12 @@ var Parser = function Parser(context, imports, fileInfo) {
                         argsComma.push({ name:nameLoop, value:value, expand:expand });
 
                         if (parserInput.$char(',')) {
+                            hasSep = true;
                             continue;
                         }
+                        hasSep = parserInput.$char(';') === ';';
 
-                        if (parserInput.$char(';') || isSemiColonSeparated) {
+                        if (hasSep || isSemiColonSeparated) {
 
                             if (expressionContainsNamed) {
                                 error('Cannot mix ; and , as delimiter types');
diff --git a/test/less/errors/mixin-not-defined-2.less b/test/less/errors/mixin-not-defined-2.less
new file mode 100644
index 00000000..867f81c0
--- /dev/null
+++ b/test/less/errors/mixin-not-defined-2.less
@@ -0,0 +1,7 @@
+.non-matching-mixin(@a @b) {
+  args: @a @b;  
+}
+
+x {
+  .non-matching-mixin(x, y);
+}
\ No newline at end of file
diff --git a/test/less/errors/mixin-not-defined-2.txt b/test/less/errors/mixin-not-defined-2.txt
new file mode 100644
index 00000000..2d1ad850
--- /dev/null
+++ b/test/less/errors/mixin-not-defined-2.txt
@@ -0,0 +1,4 @@
+RuntimeError: No matching definition was found for `.non-matching-mixin(x, y)` in {path}mixin-not-defined-2.less on line 6, column 3:
+5 x {
+6   .non-matching-mixin(x, y);
+7 }