diff --git a/apache/lib/common b/apache/lib/common
index 3bf0109..dc72b51 100644
--- a/apache/lib/common
+++ b/apache/lib/common
@@ -616,44 +616,9 @@ EOF
 
 
 _get_custom_rules() {
-    local cfg="$1" custom_rules type elt value first
-    custom_rules=$(e "$cfg" | cfg-get-value apache-custom-rules 2>/dev/null) || true
-    if [ -z "$custom_rules" -o "$custom_rules" == "None" ]; then
-        return 0
-    fi
-    type=$(echo "$custom_rules" | shyaml get-type)
-    value=
-    case "$type" in
-        "sequence")
-            first=1
-            while read-0 elt; do
-                elt="$(echo "$elt" | yaml_get_interpret)" || return 1
-                [ "$elt" ] || continue
-                if [ "$first" ]; then
-                    first=
-                else
-                    value+=$'\n'
-                fi
-                first=
-                value+="$elt"
-            done < <(echo "$custom_rules" | shyaml -y get-values-0)
-            ;;
-        "struct")
-            while read-0 _key val; do
-                value+=$'\n'"$(echo "$val" | yaml_get_interpret)" || return 1
-            done < <(echo "$custom_rules" | shyaml -y key-values-0)
-            ;;
-        "str")
-            value+=$(echo "$custom_rules")
-            ;;
-        "NoneType")
-            value=""
-            ;;
-        *)
-            value+=$(echo "$custom_rules")
-            ;;
-    esac
-    printf "%s" "$value"
+    local cfg="$1" custom_rules
+    custom_rules=$(e "$cfg" | shyaml -y -q get-value apache-custom-rules 2>/dev/null) || true
+    e "$custom_rules" | yaml_get_values
 }
 
 
diff --git a/apache/test/custom_rules b/apache/test/custom_rules
index 1207838..df1d80e 100644
--- a/apache/test/custom_rules
+++ b/apache/test/custom_rules
@@ -2,6 +2,21 @@
 
 exname=$(basename $0)
 
+compose_core=$(which compose-core) || {
+    echo "Requires compose-core executable to be in \$PATH." >&2
+    exit 1
+}
+
+fetch-def() {
+    local path="$1" fname="$2"
+    ( . "$path" 1>&2 || {
+          echo "Failed to load '$path'." >&2
+          exit 1
+      }
+      declare -f "$fname"
+    )
+}
+
 prefix_cmd="
 . /etc/shlib
 
@@ -10,7 +25,13 @@ include parse
 
 . ../lib/common
 
-"
+$(fetch-def "$compose_core" yaml_get_values)
+$(fetch-def "$compose_core" yaml_get_interpret)
+
+" || {
+    echo "Couldn't build prefix cmd" >&2
+    exit 1
+}
 
 # mock
 cfg-get-value() {
diff --git a/apache/test/vhost b/apache/test/vhost
index 8e812e0..58e150d 100644
--- a/apache/test/vhost
+++ b/apache/test/vhost
@@ -2,6 +2,22 @@
 
 exname=$(basename $0)
 
+compose_core=$(which compose-core) || {
+    echo "Requires compose-core executable to be in \$PATH." >&2
+    exit 1
+}
+
+fetch-def() {
+    local path="$1" fname="$2"
+    ( . "$path" 1>&2 || {
+          echo "Failed to load '$path'." >&2
+          exit 1
+      }
+      declare -f "$fname"
+    )
+}
+
+
 prefix_cmd="
 . /etc/shlib
 
@@ -10,7 +26,16 @@ include parse
 
 . ../lib/common
 
-"
+$(fetch-def "$compose_core" yaml_get_values)
+$(fetch-def "$compose_core" yaml_get_interpret)
+
+" || {
+    echo "Couldn't build prefix cmd" >&2
+    exit 1
+}
+
+
+
 
 # mock
 relation-get() {
diff --git a/apache/test/vhost_cert_provider b/apache/test/vhost_cert_provider
index 093175d..6754dba 100644
--- a/apache/test/vhost_cert_provider
+++ b/apache/test/vhost_cert_provider
@@ -2,6 +2,22 @@
 
 exname=$(basename $0)
 
+compose_core=$(which compose-core) || {
+    echo "Requires compose-core executable to be in \$PATH." >&2
+    exit 1
+}
+
+fetch-def() {
+    local path="$1" fname="$2"
+    ( . "$path" 1>&2 || {
+          echo "Failed to load '$path'." >&2
+          exit 1
+      }
+      declare -f "$fname"
+    )
+}
+
+
 prefix_cmd="
 . /etc/shlib
 
@@ -10,9 +26,14 @@ include parse
 
 . ../lib/common
 
-depends compose
+$(fetch-def "$compose_core" yaml_get_values)
+$(fetch-def "$compose_core" yaml_get_interpret)
+
+" || {
+    echo "Couldn't build prefix cmd" >&2
+    exit 1
+}
 
-"
 
 ##
 ## Mocks
diff --git a/apache/test/vhost_files b/apache/test/vhost_files
index 3a2884b..4a17fa5 100644
--- a/apache/test/vhost_files
+++ b/apache/test/vhost_files
@@ -2,6 +2,21 @@
 
 exname=$(basename $0)
 
+compose_core=$(which compose-core) || {
+    echo "Requires compose-core executable to be in \$PATH." >&2
+    exit 1
+}
+
+fetch-def() {
+    local path="$1" fname="$2"
+    ( . "$path" 1>&2 || {
+          echo "Failed to load '$path'." >&2
+          exit 1
+      }
+      declare -f "$fname"
+    )
+}
+
 prefix_cmd="
 . /etc/shlib
 
@@ -10,7 +25,14 @@ include parse
 
 . ../lib/common
 
-"
+$(fetch-def "$compose_core" yaml_get_values)
+$(fetch-def "$compose_core" yaml_get_interpret)
+
+" || {
+    echo "Couldn't build prefix cmd" >&2
+    exit 1
+}
+
 
 ##
 ## Mocks