      initialize_boost()
      initialize_llvm_bazel()
 diff --git a/dependency_support/pip_requirements.txt b/dependency_support/pip_requirements.txt
-index 51165306..e69de29b 100644
+deleted file mode 100644
+index 7a1e5df7..00000000
 --- a/dependency_support/pip_requirements.txt
-+++ b/dependency_support/pip_requirements.txt
++++ /dev/null
 @@ -1,16 +0,0 @@
 -pycparser==2.19
 -Flask==1.1.2

         "//xls/common:runfiles",
         "@com_google_absl_py//absl:app",
         "@com_google_absl_py//absl/flags",
@@ -169,8 +165,6 @@ py_library(
     srcs_version = "PY3ONLY",
     deps = [
         ":delay_model_py_pb2",

-# Note: numpy and scipy version availability seems to differ between Ubuntu
-# versions that we want to support (e.g. 18.04 vs 20.04), so we accept a
-# range that makes successful installation on those platforms possible.
-numpy>=1.21
-scipy>=1.5.4,<=1.6.0
diff --git a/xls/delay_model/BUILD b/xls/delay_model/BUILD
index f7c941f2..db9315fd 100644
--- a/xls/delay_model/BUILD
+++ b/xls/delay_model/BUILD
@@ -12,8 +12,6 @@
