diff --git a/src/babel/__snapshots__/plugin.test.js.snap b/src/babel/__snapshots__/plugin.test.js.snap
index 3f990b3..8b94608 100644
--- a/src/babel/__snapshots__/plugin.test.js.snap
+++ b/src/babel/__snapshots__/plugin.test.js.snap
@@ -192,14 +192,14 @@ const node = function (state) {
       return;
     }
 
-    loop_3: for (;;) {
+    group_3: for (;;) {
       var y3 = state.y,
           x3 = state.x;
 
       if ((x = _node_expression3(state)) == null) {
         state.y = y3;
         state.x = x3;
-        break loop_3;
+        break group_3;
       }
     }
   }
@@ -277,7 +277,7 @@ const node = function (state) {
         break block_2;
       }
 
-      loop_2: for (;;) {
+      group_2: for (;;) {
         var y2 = state.y,
             x2 = state.x;
 
@@ -286,7 +286,7 @@ const node = function (state) {
         } else {
           state.y = y2;
           state.x = x2;
-          break loop_2;
+          break group_2;
         }
       }
 
@@ -301,7 +301,7 @@ const node = function (state) {
       return;
     }
 
-    loop_2: for (;;) {
+    group_2: for (;;) {
       var y2 = state.y,
           x2 = state.x;
 
@@ -310,11 +310,11 @@ const node = function (state) {
       } else {
         state.y = y2;
         state.x = x2;
-        break loop_2;
+        break group_2;
       }
     }
 
-    loop_2: for (;;) {
+    group_2: for (;;) {
       var y2 = state.y,
           x2 = state.x;
       var ln2 = node.length;
@@ -325,17 +325,21 @@ const node = function (state) {
         state.y = y2;
         state.x = x2;
         node.length = ln2;
-        break loop_2;
+        break group_2;
       }
 
-      var y4 = state.y,
-          x4 = state.x;
+      group_4: {
+        var y4 = state.y,
+            x4 = state.x;
 
-      if ((x = _node_expression4(state)) != null) {
-        node.push(x);
-      } else {
-        state.y = y4;
-        state.x = x4;
+        if ((x = _node_expression4(state)) != null) {
+          node.push(x);
+        } else {
+          state.y = y4;
+          state.x = x4;
+          node.length = ln2;
+          break group_4;
+        }
       }
 
       if ((x = _node_expression5(state)) != null) {
@@ -344,7 +348,7 @@ const node = function (state) {
         state.y = y2;
         state.x = x2;
         node.length = ln2;
-        break loop_2;
+        break group_2;
       }
     }
   }
diff --git a/src/codegen.js b/src/codegen.js
index 9349e2e..3160391 100644
--- a/src/codegen.js
+++ b/src/codegen.js
@@ -71,7 +71,7 @@ const astChild = (ast, depth, opts) =>
 const astQuantifier = (ast, depth, opts) => {
   const { index, abort } = opts;
   const invert = `inv_${depth}`;
-  const loop = `loop_${depth}`;
+  const group = `group_${depth}`;
 
   opts = copy(opts);
   if (ast.capture === '!') {
@@ -90,21 +90,23 @@ const astQuantifier = (ast, depth, opts) => {
   } else if (ast.quantifier === '*') {
     opts.length = 0;
     opts.index = depth;
-    opts.abort = js`break ${loop};`;
+    opts.abort = js`break ${group};`;
 
     child = js`
-      ${loop}: for (;;) {
+      ${group}: for (;;) {
         ${assignIndex(depth)}
         ${astChild(ast, depth, opts)}
       }
     `;
   } else if (ast.quantifier === '?') {
     opts.index = depth;
-    opts.abort = '';
+    opts.abort = js`break ${group}`;
 
     child = js`
-      ${assignIndex(depth)}
-      ${astChild(ast, depth, opts)}
+      ${group}: {
+        ${assignIndex(depth)}
+        ${astChild(ast, depth, opts)}
+      }
     `;
   } else {
     child = astChild(ast, depth, opts);
diff --git a/src/core.test.js b/src/core.test.js
index 9333647..0892b11 100644
--- a/src/core.test.js
+++ b/src/core.test.js
@@ -115,6 +115,7 @@ describe('optional group then required matcher', () => {
     input    | result
     ${'123'} | ${['1', '2', '3']}
     ${'3'}   | ${['3']}
+    ${'23'}  | ${undefined}
     ${'_'}   | ${undefined}
   `('should return $result when $input is passed', ({ input, result }) => {
     expectToParse(node, input, result);
@@ -128,6 +129,7 @@ describe('star group then required matcher', () => {
     ${'123'}   | ${['1', '2', '3']}
     ${'12123'} | ${['1', '2', '1', '2', '3']}
     ${'3'}     | ${['3']}
+    ${'23'}    | ${undefined}
     ${'13'}    | ${undefined}
     ${'_'}     | ${undefined}
   `('should return $result when $input is passed', ({ input, result }) => {
@@ -141,6 +143,7 @@ describe('plus group then required matcher', () => {
     input      | result
     ${'123'}   | ${['1', '2', '3']}
     ${'12123'} | ${['1', '2', '1', '2', '3']}
+    ${'23'}    | ${undefined}
     ${'3'}     | ${undefined}
     ${'13'}    | ${undefined}
     ${'_'}     | ${undefined}