diff --git a/plugins/CuraEngineBackend/StartSliceJob.py b/plugins/CuraEngineBackend/StartSliceJob.py
index 875bbe153b..b276469d09 100644
--- a/plugins/CuraEngineBackend/StartSliceJob.py
+++ b/plugins/CuraEngineBackend/StartSliceJob.py
@@ -76,7 +76,7 @@ class GcodeStartEndFormatter:
     # will be used. Alternatively, if the expression is formatted as "{[expression], [extruder_nr]}",
     # then the expression will be evaluated with the extruder stack of the specified extruder_nr.
 
-    _instruction_regex = re.compile(r"{(?P<condition>if|else|elif|endif)?\s*(?P<expression>.*?)\s*(?:,\s*(?P<extruder_nr_expr>.*))?\s*}(?P<end_of_line>\n?)")
+    _instruction_regex = re.compile(r"{(?P<condition>if|else|elif|endif)?\s*(?P<expression>[^{}]*?)\s*(?:,\s*(?P<extruder_nr_expr>[^{}]*))?\s*}(?P<end_of_line>\n?)")
 
     def __init__(self, all_extruder_settings: Dict[str, Dict[str, Any]], default_extruder_nr: int = -1) -> None:
         super().__init__()