diff --git a/src/callback.c b/src/callback.c
index f37f14ae7..c2d178819 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -6,12 +6,12 @@
 
 static struct reg {
     struct reg * next;
-    CALLBACK cb;
+    HCALLBACK cb;
     char *name;
 } *registry;
 
-CALLBACK create_callback(void (*cbv)(va_list va)) {
-    CALLBACK cb;
+HCALLBACK create_callback(void(*cbv)(va_list va)) {
+    HCALLBACK cb;
     cb.cbv = cbv;
     return cb;
 }
@@ -26,7 +26,7 @@ void reset_callbacks(void) {
     registry = 0;
 }
 
-CALLBACK register_callback(const char *name, void (*cbv)(va_list va))
+HCALLBACK register_callback(const char *name, void(*cbv)(va_list va))
 {
     struct reg * r = (struct reg *)malloc(sizeof(struct reg));
     r->next = registry;
@@ -36,7 +36,7 @@ CALLBACK register_callback(const char *name, void (*cbv)(va_list va))
     return r->cb;
 }
 
-int find_callback(const char *name, CALLBACK *result) {
+int find_callback(const char *name, HCALLBACK *result) {
     if (result && name) {
         struct reg *r;
         for (r=registry;r;r=r->next) {
@@ -49,7 +49,7 @@ int find_callback(const char *name, CALLBACK *result) {
     return -1;
 }
 
-int call_callback(CALLBACK cb, const char *name, ... ) {
+int call_callback(HCALLBACK cb, const char *name, ...) {
     va_list ap;
     if (name) {
         int err = find_callback(name, &cb);
diff --git a/src/callback.h b/src/callback.h
index b7f592161..f7b0d71ea 100644
--- a/src/callback.h
+++ b/src/callback.h
@@ -5,12 +5,12 @@
 
 typedef struct {
     void (*cbv)(va_list va);
-} CALLBACK;
+} HCALLBACK;
 
-CALLBACK register_callback(const char *name, void (*cbv)(va_list va));
-CALLBACK create_callback(void (*cbv)(va_list va));
-int find_callback(const char *name, CALLBACK *result);
-int call_callback(CALLBACK cb, const char *name, ...);
+HCALLBACK register_callback(const char *name, void(*cbv)(va_list va));
+HCALLBACK create_callback(void(*cbv)(va_list va));
+int find_callback(const char *name, HCALLBACK *result);
+int call_callback(HCALLBACK cb, const char *name, ...);
 void reset_callbacks(void);
 
 #endif
diff --git a/src/callback.test.c b/src/callback.test.c
index b5fcba34b..fbc68ddea 100644
--- a/src/callback.test.c
+++ b/src/callback.test.c
@@ -9,7 +9,7 @@ void callback(va_list ap) {
 }
 
 static void test_find_callback(CuTest *tc) {
-    CALLBACK cb;
+    HCALLBACK cb;
     reset_callbacks();
     CuAssertIntEquals(tc, -1, find_callback("test", &cb));
     cb = register_callback("test", callback);
@@ -18,7 +18,7 @@ static void test_find_callback(CuTest *tc) {
 }
 
 static void test_call_by_handle(CuTest *tc) {
-    CALLBACK cb;
+    HCALLBACK cb;
     int x = 0;
     reset_callbacks();
     cb = create_callback(callback);
@@ -28,7 +28,8 @@ static void test_call_by_handle(CuTest *tc) {
 }
 
 static void test_call_by_name(CuTest *tc) {
-    CALLBACK cb, ca;
+    HCALLBACK cb = { 0 };
+    HCALLBACK ca = { 0 };
     int x = 0;
     reset_callbacks();
     CuAssertIntEquals(tc, -1, call_callback(cb, "test", 42, &x));