diff --git a/tests/fuzzer/virgl_fuzzer.c b/tests/fuzzer/virgl_fuzzer.c
index b8f73e2..d248f47 100644
--- a/tests/fuzzer/virgl_fuzzer.c
+++ b/tests/fuzzer/virgl_fuzzer.c
@@ -116,21 +116,26 @@ static bool initialized = false;
 static int initialize_environment()
 {
    if (!initialized) {
+      EGLBoolean ok;
+
       // Force SW rendering unless env variable is already set.
       setenv(SWRAST_ENV, "true", 0);
 
       cookie.display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
       assert(cookie.display != EGL_NO_DISPLAY);
 
-      assert(eglInitialize(cookie.display, NULL, NULL));
+      ok = eglInitialize(cookie.display, NULL, NULL);
+      assert(ok);
 
       const EGLint config_attribs[] = { EGL_SURFACE_TYPE, EGL_DONT_CARE,
                                         EGL_NONE };
       EGLint num_configs;
-      assert(eglChooseConfig(cookie.display, config_attribs,
-                             &cookie.egl_config, 1, &num_configs));
+      ok = eglChooseConfig(cookie.display, config_attribs,
+                           &cookie.egl_config, 1, &num_configs);
+      assert(ok);
 
-      assert(eglBindAPI(EGL_OPENGL_ES_API));
+      ok = eglBindAPI(EGL_OPENGL_ES_API);
+      assert(ok);
 
       const EGLint context_attribs[] = { EGL_CONTEXT_CLIENT_VERSION, 3,
                                          EGL_NONE };
@@ -138,8 +143,9 @@ static int initialize_environment()
                                     EGL_NO_CONTEXT, context_attribs);
       assert(cookie.ctx != EGL_NO_CONTEXT);
 
-      assert(eglMakeCurrent(cookie.display, EGL_NO_SURFACE, EGL_NO_SURFACE,
-                            cookie.ctx));
+      ok = eglMakeCurrent(cookie.display, EGL_NO_SURFACE, EGL_NO_SURFACE,
+                          cookie.ctx);
+      assert(ok);
 
       initialized = true;
    }
@@ -166,6 +172,7 @@ static void cleanup_environment()
 int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
 {
    uint32_t ctx_id = initialize_environment();
+   int ret;
 
    // There are trade-offs here between ensuring that state is not persisted
    // between invocations of virgl_renderer_submit_cmd, and to avoid leaking
@@ -173,10 +180,12 @@ int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
    // driver with each eglInitialize()/eglTerminate() if CLEANUP_EACH_INPUT
    // is set.
 
-   assert(!virgl_renderer_init(&cookie, 0, &fuzzer_cbs));
+   ret = virgl_renderer_init(&cookie, 0, &fuzzer_cbs);
+   assert(!ret);
 
    const char *name = "fuzzctx";
-   assert(!virgl_renderer_context_create(ctx_id, strlen(name), name));
+   ret = virgl_renderer_context_create(ctx_id, strlen(name), name);
+   assert(!ret);
 
    virgl_renderer_submit_cmd((void *) data, ctx_id, size / sizeof(uint32_t));