diff --git a/src/regex/lib_pcre2.cr b/src/regex/lib_pcre2.cr
index 0df60a05499b..13b451127985 100644
--- a/src/regex/lib_pcre2.cr
+++ b/src/regex/lib_pcre2.cr
@@ -207,8 +207,10 @@ lib LibPCRE2
   fun get_ovector_pointer = pcre2_get_ovector_pointer_8(match_data : MatchData*) : LibC::SizeT*
   fun get_ovector_count = pcre2_get_ovector_count_8(match_data : MatchData*) : UInt32
 
-  # void *private_malloc(Int, void *);
-  # void  private_free(void *, void *);
-  fun general_context_create = pcre2_general_context_create_8(private_malloc : Void*, private_free : Void*, memory_data : Void*) : GeneralContext
+  fun general_context_create = pcre2_general_context_create_8(
+    private_malloc : LibC::SizeT, Void* -> Void,
+    private_free : Void*, Void* -> Void,
+    memory_data : Void*
+  ) : GeneralContext
   fun config = pcre2_config_8(what : UInt32, where : Void*) : Int
 end
diff --git a/src/regex/pcre2.cr b/src/regex/pcre2.cr
index 14b64e72546d..ba880ea6902f 100644
--- a/src/regex/pcre2.cr
+++ b/src/regex/pcre2.cr
@@ -135,7 +135,7 @@ module Regex::PCRE2
   end
 
   class_getter general_context do
-    LibPCRE2.general_context_create(->(size : LibC::Int, data : Void*) { GC.malloc(size) }.pointer, ->(pointer : Void*, data : Void*) { GC.free(pointer) }.pointer, nil)
+    LibPCRE2.general_context_create(->(size, _data) { GC.malloc(size) }, ->(pointer, _data) { GC.free(pointer) }, nil)
   end
 
   # Returns a JIT stack that's shared in the current thread.