diff --git a/engine/slc.h b/engine/slc.h
index 809ec30..221b51f 100644
--- a/engine/slc.h
+++ b/engine/slc.h
@@ -11,6 +11,7 @@ struct wordstart {
 	/* char vars[]; // The local variables of the word. */
 	/* char data[]; // The "body" of the word - either text source or after processing the threaded code of it (see flags) */
 };
+typedef struct wordstart wordstart;
 
 enum SLC_SYM_OP { SLC_SYM_SET, SLC_SYM_GET, SLC_SYM_ERASE };
 enum SLC_STACK_OP { SLC_STACK_PUSH, SLC_STACK_POP, SLC_STACK_AT, SLC_STACK_COUNT, SLC_STACK_ERASE };
@@ -41,7 +42,7 @@ enum SLC_IO_OP {
  * @param word When adding a found word to the symbol table, the key will point to this word
  * @returns The word definition stored for the key, or NULL when it is not stored yet or op is SET and there was an error.
  */
-typedef wordstart* (*sym)(SLC_SYM_OP op, char *key, wordstart *word);
+typedef wordstart* (*sym)(enum SLC_SYM_OP op, char *key, wordstart *word);
 
 /**
  * Function-abstraction for an integer "stack".
@@ -58,7 +59,7 @@ typedef wordstart* (*sym)(SLC_SYM_OP op, char *key, wordstart *word);
  * @param param On SLC_STACK_PUSH, this is the element to push onto the stack, in case of SLC_STACK_AT, its the index.
  * @return The element at the given stack location in case of SLC_STACK_AT or the count in case of SLC_STACK_COUNT. Can show error!
  */
-typedef uint32_t (*stack)(SLC_STACK_OP op, uint32_t param);
+typedef uint32_t (*stack)(enum SLC_STACK_OP op, uint32_t param);
 
 /**
  * Function-abstraction for an integer "session-storage".
@@ -72,7 +73,7 @@ typedef uint32_t (*stack)(SLC_STACK_OP op, uint32_t param);
  * @param i Used on SESSION_GET and is the accessor index
  * @returns The accessor index in case of ALLOC (0xFFFFFFFF == -1 means error), on get it returns the store BYTE as uint32_t
  */
-typedef uint32_t (*session)(SLC_SESSION_OP op, uint32_t i);
+typedef uint32_t (*session)(enum SLC_SESSION_OP op, uint32_t i);
 
 /**
  * Function-abstraction for io connectors.
@@ -93,7 +94,7 @@ typedef uint32_t (*session)(SLC_SESSION_OP op, uint32_t i);
  * @param param The name or temporary name or command or the handle pointer parameter depending on op.
  * @returns A handle pointer or pointer to character to read / written or closed/unlocked handle (NULL on errors). Also cmd stdout.
  */
-typedef const char* (*ioconn)(SLC_IO_OP op, const char *param);
+typedef const char* (*ioconn)(enum SLC_IO_OP op, const char *param);
 
 /**
  * This function runs the main slc engine over a snippet of code.
@@ -116,9 +117,9 @@ void slc(
 	ioconn io_connector,
 	const char *prefix,
 	const char *ender,
-	const char *varprefix,
+	const char *varprefix
 ) {
 	// TODO
 }
 
-#ENDIF /* SLC_H */
+#endif /* SLC_H */