diff --git a/scripts/install_anr.sh b/scripts/install_anr.sh
index 148321dee50..b3d02beb853 100755
--- a/scripts/install_anr.sh
+++ b/scripts/install_anr.sh
@@ -9,9 +9,6 @@ AVALANCHE_PATH=$(
   cd .. && pwd
 )
 
-# Load the constants
-source "$AVALANCHE_PATH"/scripts/constants.sh
-
 #################################
 # download avalanche-network-runner
 # https://github.com/ava-labs/avalanche-network-runner
diff --git a/scripts/tests.e2e.sh b/scripts/tests.e2e.sh
index 67fd1b538b7..ce93100c0c7 100755
--- a/scripts/tests.e2e.sh
+++ b/scripts/tests.e2e.sh
@@ -23,6 +23,12 @@ echo "installing avalanche-network-runner"
 ANR_WORKDIR="/tmp"
 ./scripts/install_anr.sh
 
+# Sourcing constants.sh ensures that the necessary CGO flags are set to
+# build the portable version of BLST. Without this, ginkgo may fail to
+# build the test binary if run on a host (e.g. github worker) that lacks
+# the instructions to build non-portable BLST.
+source ./scripts/constants.sh
+
 #################################
 echo "building e2e.test"
 # to install the ginkgo binary (required for test build and run)
diff --git a/scripts/tests.upgrade.sh b/scripts/tests.upgrade.sh
index 14cba2b2a0e..da42ce3262b 100755
--- a/scripts/tests.upgrade.sh
+++ b/scripts/tests.upgrade.sh
@@ -56,6 +56,12 @@ echo "installing avalanche-network-runner"
 ANR_WORKDIR="/tmp"
 ./scripts/install_anr.sh
 
+# Sourcing constants.sh ensures that the necessary CGO flags are set to
+# build the portable version of BLST. Without this, ginkgo may fail to
+# build the test binary if run on a host (e.g. github worker) that lacks
+# the instructions to build non-portable BLST.
+source ./scripts/constants.sh
+
 #################################
 echo "building upgrade.test"
 # to install the ginkgo binary (required for test build and run)