diff --git a/install-scripts/install-safe-chain.ps1 b/install-scripts/install-safe-chain.ps1
index 3c43861..f870123 100644
--- a/install-scripts/install-safe-chain.ps1
+++ b/install-scripts/install-safe-chain.ps1
@@ -38,7 +38,7 @@ function Test-InstallDir {
 }
 
 $Version = $env:SAFE_CHAIN_VERSION  # Will be fetched from latest release if not set
-$SafeChainBase = if ($InstallDir) { $InstallDir } else { Join-Path $env:USERPROFILE ".safe-chain" }
+$SafeChainBase = if ($InstallDir) { $InstallDir } else { Join-Path $HOME ".safe-chain" }
 
 $installDirValidation = Test-InstallDir -Dir $SafeChainBase
 if (-not $installDirValidation.Ok) {
diff --git a/packages/safe-chain/src/shell-integration/path-wrappers/templates/unix-wrapper.template.sh b/packages/safe-chain/src/shell-integration/path-wrappers/templates/unix-wrapper.template.sh
index 9275230..2547a01 100644
--- a/packages/safe-chain/src/shell-integration/path-wrappers/templates/unix-wrapper.template.sh
+++ b/packages/safe-chain/src/shell-integration/path-wrappers/templates/unix-wrapper.template.sh
@@ -5,6 +5,10 @@
 # Function to remove shim from PATH (POSIX-compliant)
 remove_shim_from_path() {
     _safe_chain_shims=$(CDPATH= cd -- "$(dirname -- "$0")" 2>/dev/null && pwd -P)
+    if [ -z "$_safe_chain_shims" ]; then
+        echo "$PATH"
+        return
+    fi
     echo "$PATH" | sed "s|${_safe_chain_shims}:||g"
 }
 
diff --git a/packages/safe-chain/src/shell-integration/startup-scripts/init-fish.fish b/packages/safe-chain/src/shell-integration/startup-scripts/init-fish.fish
index e0cc9ec..4469d3f 100644
--- a/packages/safe-chain/src/shell-integration/startup-scripts/init-fish.fish
+++ b/packages/safe-chain/src/shell-integration/startup-scripts/init-fish.fish
@@ -1,5 +1,6 @@
 set -l safe_chain_script (status filename)
-set -l safe_chain_base (path dirname (path dirname $safe_chain_script))
+set -l safe_chain_scripts_dir (dirname $safe_chain_script)
+set -l safe_chain_base (dirname $safe_chain_scripts_dir)
 set -gx PATH $PATH $safe_chain_base/bin
 
 function npx
diff --git a/packages/safe-chain/src/shell-integration/startup-scripts/init-posix.sh b/packages/safe-chain/src/shell-integration/startup-scripts/init-posix.sh
index ebc10c4..b79a31c 100644
--- a/packages/safe-chain/src/shell-integration/startup-scripts/init-posix.sh
+++ b/packages/safe-chain/src/shell-integration/startup-scripts/init-posix.sh
@@ -1,18 +1,12 @@
-_get_safe_chain_script_path() {
-    if [ -n "${BASH_SOURCE[0]:-}" ]; then
-        printf '%s\n' "${BASH_SOURCE[0]}"
-        return
-    fi
-
-    if [ -n "${ZSH_VERSION:-}" ]; then
-        eval 'printf "%s\n" "${(%):-%x}"'
-        return
-    fi
-
-    printf '%s\n' "$0"
-}
-
-_sc_script_path="$(_get_safe_chain_script_path)"
+if [ -n "${BASH_SOURCE[0]:-}" ]; then
+    _sc_script_path="${BASH_SOURCE[0]}"
+elif [ -n "${ZSH_VERSION:-}" ]; then
+    # ${(%):-%x} uses Zsh prompt expansion to get the sourced file's path.
+    # eval is required so other shells don't try to parse the Zsh-specific syntax.
+    eval '_sc_script_path="${(%):-%x}"'
+else
+    _sc_script_path="$0"
+fi
 _sc_scripts_dir=$(CDPATH= cd -- "$(dirname -- "$_sc_script_path")" 2>/dev/null && pwd -P)
 _sc_base=$(dirname -- "$_sc_scripts_dir")
 export PATH="$PATH:${_sc_base}/bin"