diff --git a/configure/CONFIG_SITE b/configure/CONFIG_SITE
index 6524618..82c7ea4 100644
--- a/configure/CONFIG_SITE
+++ b/configure/CONFIG_SITE
@@ -16,10 +16,10 @@ CROSS_COMPILER_TARGET_ARCHS += linux-arm_elhf
 
 # This can either be an explicit path to the directory containing the
 # epicsdbbuilder module or a version number understood by pkg_resources.require
-EPICSDBBUILDER ?= /dls_sw/prod/python3/RHEL7-x86_64/epicsdbbuilder/1.5
+EPICSDBBUILDER = /dls_sw/prod/python3/RHEL7-x86_64/epicsdbbuilder/1.5
 
-SPHINXBUILD ?= /dls_sw/prod/python3/RHEL7-x86_64/sphinx/2.3.1/prefix/bin/sphinx-build
+SPHINXBUILD = /dls_sw/prod/python3/RHEL7-x86_64/sphinx/2.3.1/prefix/bin/sphinx-build
 
-PYTHON ?= python
+PYTHON = python
 
 # vim: set filetype=make:
diff --git a/configure/RELEASE b/configure/RELEASE
index cdc5d59..3bb4a81 100644
--- a/configure/RELEASE
+++ b/configure/RELEASE
@@ -22,4 +22,4 @@
 
 # EPICS_BASE usually appears last so other apps can override stuff.
 # Point this to the EPICS installation.
-EPICS_BASE ?= /dls_sw/epics/R3.14.12.7/base
+EPICS_BASE = /dls_sw/epics/R3.14.12.7/base