diff --git a/src/mcp/mcp.c b/src/mcp/mcp.c
index 36afeb6f8..3785f5f87 100644
--- a/src/mcp/mcp.c
+++ b/src/mcp/mcp.c
@@ -10419,6 +10419,13 @@ static void release_request_store(cbm_mcp_server_t *srv) {
     srv->store = NULL;
     free(srv->current_project);
     srv->current_project = NULL;
+    /* The close above frees a connection's worth of page cache. Ask the
+     * allocator to hand those pages back now, which keeps a long-lived daemon
+     * flat across thousands of request-scoped stores (#581). This only became
+     * meaningful once the Windows interposer made the pages mimalloc's: an
+     * earlier attempt aimed at the CRT heap instead and could not release
+     * them. POSIX already purges on free, so this is a no-op there. */
+    cbm_mem_collect();
 }
 
 char *cbm_mcp_handle_tool(cbm_mcp_server_t *srv, const char *tool_name, const char *args_json) {