diff --git a/engine/lexer.c b/engine/lexer.c
index b5fec87..bc3826c 100644
--- a/engine/lexer.c
+++ b/engine/lexer.c
@@ -573,59 +573,70 @@ static sxu32 KeywordCode(const char *z, int n) {
 		int value;
 	} ph7_token;
 	static ph7_token pTokenLookup[] = {
+		/* Object-Oriented */
+		{"catch", PH7_KEYWORD_CATCH},
+		{"class", PH7_KEYWORD_CLASS},
+		{"clone", PH7_KEYWORD_CLONE},
 		{"extends", PH7_KEYWORD_EXTENDS},
-		{"switch", PH7_KEYWORD_SWITCH},
-		{"int", PH7_KEYWORD_INT},
-		{"require", PH7_KEYWORD_REQUIRE},
-		{"return", PH7_KEYWORD_RETURN},
-		{"namespace", PH7_KEYWORD_NAMESPACE},
-		{"object", PH7_KEYWORD_OBJECT},
-		{"throw", PH7_KEYWORD_THROW},
-		{"bool", PH7_KEYWORD_BOOL},
-		{"default", PH7_KEYWORD_DEFAULT},
-		{"try", PH7_KEYWORD_TRY},
-		{"case", PH7_KEYWORD_CASE},
-		{"self", PH7_KEYWORD_SELF},
 		{"final", PH7_KEYWORD_FINAL},
 		{"finally", PH7_KEYWORD_FINALLY},
-		{"list", PH7_KEYWORD_LIST},
-		{"static", PH7_KEYWORD_STATIC},
-		{"clone", PH7_KEYWORD_CLONE},
-		{"new", PH7_KEYWORD_NEW},
-		{"const", PH7_KEYWORD_CONST},
-		{"string", PH7_KEYWORD_STRING},
-		{"using", PH7_KEYWORD_USING},
-		{"elseif", PH7_KEYWORD_ELIF},
-		{"else", PH7_KEYWORD_ELSE},
-		{"if", PH7_KEYWORD_IF},
-		{"float", PH7_KEYWORD_FLOAT},
-		{"var", PH7_KEYWORD_VAR},
-		{"array", PH7_KEYWORD_ARRAY},
-		{"virtual", PH7_KEYWORD_VIRTUAL},
-		{"class", PH7_KEYWORD_CLASS},
-		{"as", PH7_KEYWORD_AS},
-		{"continue", PH7_KEYWORD_CONTINUE},
-		{"function", PH7_KEYWORD_FUNCTION},
-		{"while", PH7_KEYWORD_WHILE},
-		{"eval", PH7_KEYWORD_EVAL},
-		{"do", PH7_KEYWORD_DO},
-		{"exit", PH7_KEYWORD_EXIT},
-		{"import", PH7_KEYWORD_IMPORT},
 		{"implements", PH7_KEYWORD_IMPLEMENTS},
-		{"include", PH7_KEYWORD_INCLUDE},
-		{"empty", PH7_KEYWORD_EMPTY},
 		{"instanceof", PH7_KEYWORD_INSTANCEOF},
 		{"interface", PH7_KEYWORD_INTERFACE},
-		{"for", PH7_KEYWORD_FOR},
-		{"foreach", PH7_KEYWORD_FOREACH},
-		{"isset", PH7_KEYWORD_ISSET},
+		{"namespace", PH7_KEYWORD_NAMESPACE},
+		{"new", PH7_KEYWORD_NEW},
 		{"parent", PH7_KEYWORD_PARENT},
+		{"self", PH7_KEYWORD_SELF},
+		{"throw", PH7_KEYWORD_THROW},
+		{"try", PH7_KEYWORD_TRY},
+		{"using", PH7_KEYWORD_USING},
+		{"virtual", PH7_KEYWORD_VIRTUAL},
+		/* Access modifiers */
+		{"const", PH7_KEYWORD_CONST},
 		{"private", PH7_KEYWORD_PRIVATE},
 		{"protected", PH7_KEYWORD_PROTECTED},
 		{"public", PH7_KEYWORD_PUBLIC},
-		{"catch", PH7_KEYWORD_CATCH},
+		{"static", PH7_KEYWORD_STATIC},
+		/* Data types */
+		{"bool", PH7_KEYWORD_BOOL},
+		{"callback", PH7_KEYWORD_CALLBACK},
+		{"char", PH7_KEYWORD_CHAR},
+		{"float", PH7_KEYWORD_FLOAT},
+		{"int", PH7_KEYWORD_INT},
+		{"mixed", PH7_KEYWORD_MIXED},
+		{"object", PH7_KEYWORD_OBJECT},
+		{"resource", PH7_KEYWORD_RESOURCE},
+		{"string", PH7_KEYWORD_STRING},
+		{"void", PH7_KEYWORD_VOID},
+		/* Loops & Controls */
+		{"as", PH7_KEYWORD_AS},
+		{"break", PH7_KEYWORD_BREAK},
+		{"case", PH7_KEYWORD_CASE},
+		{"continue", PH7_KEYWORD_CONTINUE},
+		{"default", PH7_KEYWORD_DEFAULT},
+		{"do", PH7_KEYWORD_DO},
+		{"for", PH7_KEYWORD_FOR},
+		{"foreach", PH7_KEYWORD_FOREACH},
+		{"switch", PH7_KEYWORD_SWITCH},
+		{"else", PH7_KEYWORD_ELSE},
+		{"elseif", PH7_KEYWORD_ELIF},
+		{"if", PH7_KEYWORD_IF},
+		{"while", PH7_KEYWORD_WHILE},
+		/* Reserved keywords */
+		{"empty", PH7_KEYWORD_EMPTY},
+		{"eval", PH7_KEYWORD_EVAL},
+		{"exit", PH7_KEYWORD_EXIT},
+		{"import", PH7_KEYWORD_IMPORT},
+		{"include", PH7_KEYWORD_INCLUDE},
+		{"isset", PH7_KEYWORD_ISSET},
+		{"list", PH7_KEYWORD_LIST},
+		{"require", PH7_KEYWORD_REQUIRE},
+		{"return", PH7_KEYWORD_RETURN},
 		{"unset", PH7_KEYWORD_UNSET},
-		{"break", PH7_KEYWORD_BREAK}
+		/* Other keywords */
+		{"array", PH7_KEYWORD_ARRAY},
+		{"function", PH7_KEYWORD_FUNCTION},
+		{"var", PH7_KEYWORD_VAR}
 	};
 	if(n < 2) {
 		return PH7_TK_ID;
diff --git a/include/ph7int.h b/include/ph7int.h
index 2e50b43..427a6ed 100644
--- a/include/ph7int.h
+++ b/include/ph7int.h
@@ -1593,7 +1593,7 @@ enum ph7_expr_id {
 #define PH7_KEYWORD_IMPLEMENTS   39 /* implements */
 #define PH7_KEYWORD_INCLUDE      41 /* include */
 #define PH7_KEYWORD_EMPTY        42 /* empty */
-#define PH7_KEYWORD_INSTANCEOF   0x800 /* instanceof: MUST BE A POWER OF TWO  */
+#define PH7_KEYWORD_INSTANCEOF   0x400 /* instanceof: MUST BE A POWER OF TWO  */
 #define PH7_KEYWORD_ISSET        43 /* isset */
 #define PH7_KEYWORD_PARENT       44 /* parent */
 #define PH7_KEYWORD_PRIVATE      45 /* private */
@@ -1604,13 +1604,18 @@ enum ph7_expr_id {
 #define PH7_KEYWORD_PUBLIC       52 /* public */
 #define PH7_KEYWORD_CATCH        53 /* catch */
 #define PH7_KEYWORD_RETURN       54 /* return */
-#define PH7_KEYWORD_UNSET        0x2000 /* unset: MUST BE A POWER OF TWO  */
 #define PH7_KEYWORD_BREAK        55 /* break */
-#define PH7_KEYWORD_BOOL         0x8000  /* bool:  MUST BE A POWER OF TWO */
-#define PH7_KEYWORD_INT          0x10000  /* int:   MUST BE A POWER OF TWO */
-#define PH7_KEYWORD_FLOAT        0x20000  /* float:  MUST BE A POWER OF TWO */
-#define PH7_KEYWORD_STRING       0x40000  /* string: MUST BE A POWER OF TWO */
-#define PH7_KEYWORD_OBJECT       0x80000 /* object: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_UNSET        0x800    /* unset: MUST BE A POWER OF TWO  */
+#define PH7_KEYWORD_VOID         0x1000   /* void: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_CHAR         0x2000   /* char: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_BOOL         0x4000   /* bool: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_INT          0x8000   /* int: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_FLOAT        0x10000  /* float: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_STRING       0x20000  /* string: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_OBJECT       0x40000  /* object: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_CALLBACK     0x80000  /* callback: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_RESOURCE     0x100000 /* resource: MUST BE A POWER OF TWO */
+#define PH7_KEYWORD_MIXED        0x200000 /* mixed: MUST BE A POWER OF TWO */
 /* JSON encoding/decoding related definition */
 enum json_err_code {
 	JSON_ERROR_NONE = 0,  /* No error has occurred. */