diff --git a/proc/readproc.c b/proc/readproc.c
index 356c6a68..4811baba 100644
--- a/proc/readproc.c
+++ b/proc/readproc.c
@@ -318,6 +318,7 @@ int read_cmdline(char *restrict const dst, unsigned sz, unsigned pid){
         if(n==sz) break; // filled the buffer
         if(r==0) break;  // EOF
     }
+    close(fd);
     if(n){
         int i;
         if(n==sz) n--;