diff --git a/external/external_python_build.cmake b/external/external_python_build.cmake
index 55b53fb..0d03d1a 100644
--- a/external/external_python_build.cmake
+++ b/external/external_python_build.cmake
@@ -126,7 +126,7 @@ IF(INTERNAL_HEALPY)
            "-P")
 
   ExternalProject_Add(healpy
-    DEPENDS ${PREV_PYTHON_BUILD}
+    DEPENDS cfitsio ${PREV_PYTHON_BUILD}
     URL ${HEALPY_URL}
     PREFIX ${BUILD_PREFIX}/healpy-prefix
     CONFIGURE_COMMAND echo "No configure"