diff --git a/src/nwpw/pspw/charge/GNUmakefile b/src/nwpw/pspw/charge/GNUmakefile
index 2551d2a5e4..867e2ba02a 100644
--- a/src/nwpw/pspw/charge/GNUmakefile
+++ b/src/nwpw/pspw/charge/GNUmakefile
@@ -9,7 +9,7 @@
 
       LIBRARY = libpspw.a
 
-    USES_BLAS =  pspw_charge.F pspw_efield.F
+    USES_BLAS =  pspw_charge.F pspw_efield.F pspw_cosmo.F
   LIB_DEFINES =
   LIB_INCLUDES =