diff --git a/packages/babel-plugin-transform-flow-strip-types/src/index.js b/packages/babel-plugin-transform-flow-strip-types/src/index.js
index 294ff7be1a3d..ed34e32462ef 100644
--- a/packages/babel-plugin-transform-flow-strip-types/src/index.js
+++ b/packages/babel-plugin-transform-flow-strip-types/src/index.js
@@ -25,15 +25,19 @@ export default declare(api => {
         skipStrip = false;
         let directiveFound = false;
 
-        for (const comment of (comments: Array<Object>)) {
-          if (comment.value.indexOf(FLOW_DIRECTIVE) >= 0) {
-            directiveFound = true;
-
-            // remove flow directive
-            comment.value = comment.value.replace(FLOW_DIRECTIVE, "");
-
-            // remove the comment completely if it only consists of whitespace and/or stars
-            if (!comment.value.replace(/\*/g, "").trim()) comment.ignore = true;
+        if (comments) {
+          for (const comment of (comments: Array<Object>)) {
+            if (comment.value.indexOf(FLOW_DIRECTIVE) >= 0) {
+              directiveFound = true;
+
+              // remove flow directive
+              comment.value = comment.value.replace(FLOW_DIRECTIVE, "");
+
+              // remove the comment completely if it only consists of whitespace and/or stars
+              if (!comment.value.replace(/\*/g, "").trim()) {
+                comment.ignore = true;
+              }
+            }
           }
         }
 
diff --git a/packages/babel-plugin-transform-react-jsx/src/index.js b/packages/babel-plugin-transform-react-jsx/src/index.js
index 5ae4f11e7116..75de3179168c 100644
--- a/packages/babel-plugin-transform-react-jsx/src/index.js
+++ b/packages/babel-plugin-transform-react-jsx/src/index.js
@@ -51,16 +51,18 @@ export default declare((api, options) => {
       let pragmaSet = !!options.pragma;
       let pragmaFragSet = !!options.pragmaFrag;
 
-      for (const comment of (file.ast.comments: Array<Object>)) {
-        const jsxMatches = JSX_ANNOTATION_REGEX.exec(comment.value);
-        if (jsxMatches) {
-          pragma = jsxMatches[1];
-          pragmaSet = true;
-        }
-        const jsxFragMatches = JSX_FRAG_ANNOTATION_REGEX.exec(comment.value);
-        if (jsxFragMatches) {
-          pragmaFrag = jsxFragMatches[1];
-          pragmaFragSet = true;
+      if (file.ast.comments) {
+        for (const comment of (file.ast.comments: Array<Object>)) {
+          const jsxMatches = JSX_ANNOTATION_REGEX.exec(comment.value);
+          if (jsxMatches) {
+            pragma = jsxMatches[1];
+            pragmaSet = true;
+          }
+          const jsxFragMatches = JSX_FRAG_ANNOTATION_REGEX.exec(comment.value);
+          if (jsxFragMatches) {
+            pragmaFrag = jsxFragMatches[1];
+            pragmaFragSet = true;
+          }
         }
       }