diff --git a/src/utils/thread.c b/src/utils/thread.c
index ce89cf9d..a14af559 100644
--- a/src/utils/thread.c
+++ b/src/utils/thread.c
@@ -9,10 +9,6 @@
 //
 // Author: Skal (pascal.massimino@gmail.com)
 
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
 #include <assert.h>
 #include <string.h>   // for memset()
 #include "./thread.h"
diff --git a/src/utils/thread.h b/src/utils/thread.h
index 3191890b..9afe0967 100644
--- a/src/utils/thread.h
+++ b/src/utils/thread.h
@@ -12,6 +12,10 @@
 #ifndef WEBP_UTILS_THREAD_H_
 #define WEBP_UTILS_THREAD_H_
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif
@@ -63,13 +67,13 @@ typedef struct {
 
 // Must be called first, before any other method.
 void WebPWorkerInit(WebPWorker* const worker);
-// Must be called initialize the object and spawn the thread. Re-entrant.
+// Must be called to initialize the object and spawn the thread. Re-entrant.
 // Will potentially launch the thread. Returns false in case of error.
 int WebPWorkerReset(WebPWorker* const worker);
-// Make sure the previous work is finished. Returns true if worker->had_error
-// was not set and not error condition was triggered by the working thread.
+// Makes sure the previous work is finished. Returns true if worker->had_error
+// was not set and no error condition was triggered by the working thread.
 int WebPWorkerSync(WebPWorker* const worker);
-// Trigger the thread to call hook() with data1 and data2 argument. These
+// Triggers the thread to call hook() with data1 and data2 argument. These
 // hook/data1/data2 can be changed at any time before calling this function,
 // but not be changed afterward until the next call to WebPWorkerSync().
 void WebPWorkerLaunch(WebPWorker* const worker);