diff --git a/test/any_grpc.js b/test/any_grpc.js
new file mode 100644
index 00000000..43db28af
--- /dev/null
+++ b/test/any_grpc.js
@@ -0,0 +1,29 @@
+module.exports = {};
+
+function assignExportsFromGlobal(globalField, exportsField) {
+  if (global[globalField] === 'js') {
+    module.exports[exportsField] = require('../packages/grpc-js');
+  } else if (global[globalField] === 'native') {
+    module.exports[exportsField] = require('../packages/grpc-native');
+  } else {
+    throw new Error([
+      `Invalid value for global.${globalField}: ${global.globalField}.`,
+      'If running from the command line, please --require a fixture first.'
+    ].join(' '));
+  }
+}
+
+// Set 'server' and 'client' fields on this module's exports.
+// These don't refer to the portions of the gRPC interface that are
+// relevant to an application behaving as a server or a client respectively.
+// Instead, they refer to the entire gRPC module as it's visible to the
+// application.
+// In other words, a test that simulates a gRPC client should treat
+// require('any-grpc').client as the value of require('grpc'), and would simply
+// not be expected to use server components.
+assignExportsFromGlobal('_server_implementation', 'server');
+assignExportsFromGlobal('_client_implementation', 'client');
+// Increase clarity when there's no distinction between client/server
+if (module.exports.client === module.exports.server) {
+  module.exports.all = module.exports.client;
+}
diff --git a/test/api/async_test.js b/test/api/async_test.js
index e899da56..c66f3782 100644
--- a/test/api/async_test.js
+++ b/test/api/async_test.js
@@ -20,7 +20,7 @@
 
 var assert = require('assert');
 
-var grpc = require('grpc');
+var grpc = require('../any_grpc').all;
 var math = grpc.load(
     __dirname + '/../../packages/grpc-native-core/deps/grpc/src/proto/math/math.proto').math;
 
diff --git a/test/api/credentials_test.js b/test/api/credentials_test.js
index 96879994..3bf3d5f5 100644
--- a/test/api/credentials_test.js
+++ b/test/api/credentials_test.js
@@ -22,7 +22,7 @@ var assert = require('assert');
 var fs = require('fs');
 var path = require('path');
 
-var grpc = require('grpc');
+var grpc = require('../any_grpc').all;
 
 /**
  * This is used for testing functions with multiple asynchronous calls that
diff --git a/test/api/math_client_test.js b/test/api/math_client_test.js
index 09265abf..1f4f25e6 100644
--- a/test/api/math_client_test.js
+++ b/test/api/math_client_test.js
@@ -20,7 +20,7 @@
 
 var assert = require('assert');
 
-var grpc = require('grpc');
+var grpc = require('../any_grpc').all;
 var math = require('./math/math_pb');
 var MathClient = require('./math/math_grpc_pb').MathClient;
 
diff --git a/test/api/metadata_test.js b/test/api/metadata_test.js
index 5e24f7ac..7187ee73 100644
--- a/test/api/metadata_test.js
+++ b/test/api/metadata_test.js
@@ -18,7 +18,7 @@
 
 'use strict';
 
-var Metadata = require('grpc').Metadata;
+var Metadata = require('../any_grpc').all.Metadata;
 
 var assert = require('assert');
 
diff --git a/test/api/surface_test.js b/test/api/surface_test.js
index b2072fdd..d54ff7b4 100644
--- a/test/api/surface_test.js
+++ b/test/api/surface_test.js
@@ -21,7 +21,7 @@
 var assert = require('assert');
 var _ = require('lodash');
 
-var grpc = require('grpc');
+var grpc = require('../any_grpc').all;
 
 var MathClient = grpc.load(
     __dirname + '/../../packages/grpc-native-core/deps/grpc/src/proto/math/math.proto').math.Math;
diff --git a/test/fixtures/js_js.js b/test/fixtures/js_js.js
new file mode 100644
index 00000000..e0ca3c58
--- /dev/null
+++ b/test/fixtures/js_js.js
@@ -0,0 +1,2 @@
+global._server_implementation = 'native';
+global._client_implementation = 'js';
\ No newline at end of file
diff --git a/test/fixtures/js_native.js b/test/fixtures/js_native.js
new file mode 100644
index 00000000..5088df96
--- /dev/null
+++ b/test/fixtures/js_native.js
@@ -0,0 +1,2 @@
+global._server_implementation = 'js';
+global._client_implementation = 'native';
\ No newline at end of file
diff --git a/test/fixtures/native_js.js b/test/fixtures/native_js.js
new file mode 100644
index 00000000..5088df96
--- /dev/null
+++ b/test/fixtures/native_js.js
@@ -0,0 +1,2 @@
+global._server_implementation = 'js';
+global._client_implementation = 'native';
\ No newline at end of file
diff --git a/test/fixtures/native_native.js b/test/fixtures/native_native.js
new file mode 100644
index 00000000..5b005e48
--- /dev/null
+++ b/test/fixtures/native_native.js
@@ -0,0 +1,2 @@
+global._server_implementation = 'native';
+global._client_implementation = 'native';
\ No newline at end of file
diff --git a/test/gulpfile.js b/test/gulpfile.js
index d3da5c0a..c020ff76 100644
--- a/test/gulpfile.js
+++ b/test/gulpfile.js
@@ -22,6 +22,7 @@ const execa = require('execa');
 const path = require('path');
 const del = require('del');
 const linkSync = require('../util').linkSync;
+const merge = require('merge2');
 
 // gulp-help monkeypatches tasks to have an additional description parameter
 const gulp = help(_gulp);
@@ -49,5 +50,19 @@ gulp.task('internal.test.link.add', 'Link local copies of dependencies', () => {
 });
 
 gulp.task('internal.test.test', 'Run API-level tests', () => {
-  return gulp.src(`${apiTestDir}/*.js`).pipe(mocha({reporter: 'mocha-jenkins-reporter'}));
+  // run mocha tests matching a glob with a pre-required fixture,
+  // returning the associated gulp stream
+  const runTestsWithFixture = (glob, fixture) => gulp
+    .src(glob)
+    .pipe(mocha({
+      reporter: 'mocha-jenkins-reporter',
+      require: `${testDir}/fixtures/${fixture}.js`
+    }));
+  const interopTest = `${testDir}/interop/interop_test.js`;
+  const tasks = [].concat(
+    ['native_native'/*, 'js_js'*/]
+      .map((fixture) => runTestsWithFixture(`${apiTestDir}/*.js`, fixture)),
+    ['native_native', 'native_js'/*, 'js_native', 'js_js'*/]
+      .map((fixture) => runTestsWithFixture(interopTest, fixture)))
+  return merge(tasks);
 });
diff --git a/test/interop/interop_client.js b/test/interop/interop_client.js
index 5fad82bf..f9122d35 100644
--- a/test/interop/interop_client.js
+++ b/test/interop/interop_client.js
@@ -20,10 +20,9 @@
 
 var fs = require('fs');
 var path = require('path');
-// TODO(murgatroid99): use multiple grpc implementations
-var grpc = require('grpc');
+var grpc = require('../any_grpc').client;
 var testProto = grpc.load({
-  root: __dirname + '/../../packages/grpc-native-core/deps/grpc',
+  root: __dirname + '/../../../packages/grpc-native-core/deps/grpc',
   file: 'src/proto/grpc/testing/test.proto'}).grpc.testing;
 var GoogleAuth = require('google-auth-library');
 
diff --git a/test/api/interop_sanity_test.js b/test/interop/interop_sanity_test.js
similarity index 96%
rename from test/api/interop_sanity_test.js
rename to test/interop/interop_sanity_test.js
index b3f65a03..055a5ab7 100644
--- a/test/api/interop_sanity_test.js
+++ b/test/interop/interop_sanity_test.js
@@ -18,8 +18,8 @@
 
 'use strict';
 
-var interop_server = require('../interop/interop_server.js');
-var interop_client = require('../interop/interop_client.js');
+var interop_server = require('./interop_server.js');
+var interop_client = require('./interop_client.js');
 
 var server;
 
diff --git a/test/interop/interop_server.js b/test/interop/interop_server.js
index 65bb088d..58ccacd7 100644
--- a/test/interop/interop_server.js
+++ b/test/interop/interop_server.js
@@ -22,10 +22,9 @@ var fs = require('fs');
 var path = require('path');
 var _ = require('lodash');
 var AsyncDelayQueue = require('./async_delay_queue');
-// TODO(murgatroid99): use multiple grpc implementations
-var grpc = require('grpc');
+var grpc = require('../any_grpc').server;
 var testProto = grpc.load({
-  root: __dirname + '/../../packages/grpc-native-core/deps/grpc',
+  root: __dirname + '/../../../packages/grpc-native-core/deps/grpc',
   file: 'src/proto/grpc/testing/test.proto'}).grpc.testing;
 
 var ECHO_INITIAL_KEY = 'x-grpc-test-echo-initial';