diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v1/composer.json b/tests/Composer/Test/Plugin/Fixtures/plugin-v1/composer.json
index 996e5ee3e..efc552956 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v1/composer.json
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v1/composer.json
@@ -5,5 +5,8 @@
     "autoload": { "psr-0": { "Installer": "" } },
     "extra": {
         "class": "Installer\\Plugin"
+    },
+    "require": {
+        "composer-plugin-api": "1.0.0"
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v2/composer.json b/tests/Composer/Test/Plugin/Fixtures/plugin-v2/composer.json
index c099da413..6947ddd5c 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v2/composer.json
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v2/composer.json
@@ -5,5 +5,8 @@
     "autoload": { "psr-0": { "Installer": "" } },
     "extra": {
         "class": "Installer\\Plugin2"
+    },
+    "require": {
+        "composer-plugin-api": "1.0.0"
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v3/composer.json b/tests/Composer/Test/Plugin/Fixtures/plugin-v3/composer.json
index 3ba04e6f6..5cb01d019 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v3/composer.json
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v3/composer.json
@@ -5,5 +5,8 @@
     "autoload": { "psr-0": { "Installer": "" } },
     "extra": {
         "class": "Installer\\Plugin2"
+    },
+    "require": {
+        "composer-plugin-api": "1.0.0"
     }
 }
diff --git a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/composer.json b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/composer.json
index 10387a021..982d34c7b 100644
--- a/tests/Composer/Test/Plugin/Fixtures/plugin-v4/composer.json
+++ b/tests/Composer/Test/Plugin/Fixtures/plugin-v4/composer.json
@@ -8,5 +8,8 @@
             "Installer\\Plugin1",
             "Installer\\Plugin2"
         ]
+    },
+    "require": {
+        "composer-plugin-api": "1.0.0"
     }
 }