diff --git a/init/lmod/bash b/init/lmod/bash
index 54e37946..e8d57636 100644
--- a/init/lmod/bash
+++ b/init/lmod/bash
@@ -93,7 +93,11 @@ if [ -z "$__Init_EESSI_Default_Modules" ]; then
     # (in an interactive shell PS1 is likely unset, so let's only do this if it is set)
     if [ -n "$PS1" ]; then
         export PS1
-        export EESSI_MODULE_UPDATE_PS1=1
+        if [ ! -z ${EESSI_MODULE_UPDATE_PS1} ] && [ ${EESSI_MODULE_UPDATE_PS1} -eq "0" ]; then
+            unset EESSI_MODULE_UPDATE_PS1
+        else
+            export EESSI_MODULE_UPDATE_PS1=1
+        fi
     fi
 
     # Path to top-level module tree
diff --git a/init/lmod/zsh b/init/lmod/zsh
index d2f603d2..45fc73a4 100644
--- a/init/lmod/zsh
+++ b/init/lmod/zsh
@@ -49,7 +49,11 @@ if [ -z "$__Init_EESSI_Default_Modules" ]; then
     # (in an interactive shell PS1 is likely unset, so let's only do this if it is set)
     if [ -n "$PS1" ]; then
         export PS1
-        export EESSI_MODULE_UPDATE_PS1=1
+        if [ ! -z ${EESSI_MODULE_UPDATE_PS1} ] && [ ${EESSI_MODULE_UPDATE_PS1} -eq "0" ]; then
+            unset EESSI_MODULE_UPDATE_PS1
+        else
+            export EESSI_MODULE_UPDATE_PS1=1
+        fi
     fi
 
     # Path to top-level module tree