diff --git a/tools/isobuild/compiler-plugin.js b/tools/isobuild/compiler-plugin.js
index 207a21c026..454cdcdf08 100644
--- a/tools/isobuild/compiler-plugin.js
+++ b/tools/isobuild/compiler-plugin.js
@@ -384,10 +384,30 @@ class ResourceSlot {
     // contained by a node_modules directory will already have been
     // marked lazy in PackageSource#_inferFileOptions. Same for
     // non-test files if running unit tests (`meteor test-app --unit`)
-    return this.packageSourceBatch.useMeteorInstall &&
+    if (!this.packageSourceBatch.useMeteorInstall) {
+      return false;
+    }
+
+    const dirs =
       files.pathDirname(this.inputResource.path)
-        .split(files.pathSep)
-        .indexOf("imports") >= 0;
+        .split(files.pathSep);
+
+    const isInImports = dirs.indexOf("imports") >= 0;
+
+    if (global.testCommandMetadata &&
+        (global.testCommandMetadata.isUnitTest ||
+         global.testCommandMetadata.isIntegrationTest)) {
+      const isTestFile = _.any(dirs, (dir) =>
+                               /\.tests?\./.test(dir) ||
+                               /^tests?\./.test(dir) ||
+                               /^tests$/.test(dir));
+
+      // test files should always be included, if we're running app
+      // tests.
+      return isInImports && !isTestFile;
+    } else {
+      return isInImports;
+    }
   }
 
   addStylesheet(options) {
diff --git a/tools/isobuild/package-source.js b/tools/isobuild/package-source.js
index a7b6a7db72..9d2e283235 100644
--- a/tools/isobuild/package-source.js
+++ b/tools/isobuild/package-source.js
@@ -1344,7 +1344,7 @@ _.extend(PackageSource.prototype, {
 
     // If running in unit test mode (`meteor test-app --unit`), all
     // files other than test files should be loaded lazily
-    if (global.testCommandMetadata && testCommandMetadata.isUnitTest) {
+    if (global.testCommandMetadata && global.testCommandMetadata.isUnitTest) {
       const isTestFile = _.any(dirs, (dir) =>
                                /\.tests?\./.test(dir) ||
                                /^tests?\./.test(dir) ||