diff --git a/libc/src/signal/linux/CMakeLists.txt b/libc/src/signal/linux/CMakeLists.txt
--- a/libc/src/signal/linux/CMakeLists.txt
+++ b/libc/src/signal/linux/CMakeLists.txt
@@ -35,6 +35,7 @@
     ../sigemptyset.h
   DEPENDS
     __errno_location
+    errno_h
     signal_h
 )
 
@@ -47,5 +48,6 @@
     ../sigaddset.h
   DEPENDS
     __errno_location
+    errno_h
     signal_h
 )