diff --git a/syntax_files/php.yaml b/syntax_files/php.yaml
index 0d239d2..a5ab9ea 100644
--- a/syntax_files/php.yaml
+++ b/syntax_files/php.yaml
@@ -19,16 +19,16 @@ rules:
     - comment: "<!--.+?-->"
     - default: "<\\?(php|=)\" end=\"\\?>"
     - identifier.class: "([a-zA-Z0-9_-]+)\\("
-    - preproc: "(require|include|require_once|include_once)"
-    - type: "\\b(var|class|extends|function|function_exists|phpinfo|echo|case|default|exit|switch|extends|as|define|do|declare|in|trait|interface|[E|e]xception|array|int|string|bool|iterable|void)\\b"
+    - preproc: "^\\s*(require|include|require_once|include_once)"
     - identifier.class: "[a-zA-Z\\\\]+::"
     - identifier: "([A-Z][a-zA-Z0-9_]+)\\s"
     - identifier: "([A-Z0-9_]+)[;|\\s|\\)|,]"
     - type.keyword: "(global|public|private|protected|static|const)"
-    - statement: "(implements|abstract|instanceof|if|else(if)?|endif|namespace|use|as|new|throw|catch|try|while|print|for|(end)?(foreach)?)\\b"
+    - type: "\\b(var|class|extends|function|function_exists|__construct|phpinfo|echo|case|default|exit|switch|extends|as|define|do|declare|in|trait|interface|[E|e]xception|array|int|string|bool|iterable|void)\\b"
+    - statement: "(^|[[:space:]])(implements|abstract|instanceof|if|else(if)?|endif|namespace|use|as|new|throw|catch|try|while|print|for|(end)?(foreach)?)\\b"
     - identifier: "new\\s([a-zA-Z0-9\\\\]+)"
     - special: "(break|continue|goto|return)"
-    - constant.bool: "(true|false|null|TRUE|FALSE|NULL)"
+    - constant.bool: "(=|[[:space:]])(true|false|null|TRUE|FALSE|NULL)"
     - constant: "[\\s|=|\\s|\\(|/|+|-|\\*|\\[]"
     - constant.number: "[0-9]"
     - identifier: "(\\$this|parent|self|\\$this->)"