diff --git a/layouts/partials/dependencies/mathjax.html b/layouts/partials/dependencies/mathjax.html
index 3b0b0913b4..89f5957643 100644
--- a/layouts/partials/dependencies/mathjax.html
+++ b/layouts/partials/dependencies/mathjax.html
@@ -34,9 +34,9 @@
       }
       useMathJax( JSON.parse({{ $init }}) );
     </script>
-  {{- if isset .Params "custommathjaxurl" }}
+  {{- if and (isset .Params "custommathjaxurl") .Params.customMathJaxURL }}
     <script id="MathJax-script" async src="{{ .Params.customMathJaxURL }}"></script>
-  {{- else if isset .Site.Params "custommathjaxurl" }}
+  {{- else if and (isset .Site.Params "custommathjaxurl") .Site.Params.customMathJaxURL }}
     <script id="MathJax-script" async src="{{ .Site.Params.customMathJaxURL }}"></script>
   {{- else }}
     <script id="MathJax-script" async src="{{"js/mathjax/tex-mml-chtml.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}"></script>
diff --git a/layouts/partials/dependencies/mermaid.html b/layouts/partials/dependencies/mermaid.html
index 8dc42af60a..435bf870a8 100644
--- a/layouts/partials/dependencies/mermaid.html
+++ b/layouts/partials/dependencies/mermaid.html
@@ -10,9 +10,9 @@
     <script src="{{"js/d3/d3-transition.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}" defer></script>
     <script src="{{"js/d3/d3-zoom.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}" defer></script>
     <script src="{{"js/js-yaml.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}" defer></script>
-  {{- if isset .Params "custommermaidurl" }}
+  {{- if and (isset .Params "custommermaidurl") .Params.customMermaidURL }}
     <script src="{{ .Params.customMermaidURL }}" defer></script>
-  {{- else if isset .Site.Params "custommermaidurl" }}
+  {{- else if and (isset .Site.Params "custommermaidurl") .Site.Params.customMermaidURL }}
     <script src="{{ .Site.Params.customMermaidURL }}" defer></script>
   {{- else }}
     <script src="{{"js/mermaid.min.js" | relURL}}{{ if not .Site.Params.disableAssetsBusting }}?{{ now.Unix }}{{ end }}" defer></script>
diff --git a/layouts/partials/dependencies/openapi.html b/layouts/partials/dependencies/openapi.html
index 18dd29bd3a..bbf94eac32 100644
--- a/layouts/partials/dependencies/openapi.html
+++ b/layouts/partials/dependencies/openapi.html
@@ -1,9 +1,9 @@
 {{- $page := .page }}
 {{- with $page }}
   {{- $urlOpenapi := "" }}
-  {{- if isset .Params "customopenapiurl" }}
+  {{- if and (isset .Params "customopenapiurl") .Params.customOpenapiURL }}
     {{- $urlOpenapi = .Params.customOpenapiURL }}
-  {{- else if isset .Site.Params "customopenapiurl" }}
+  {{- else if and (isset .Site.Params "customopenapiurl") .Site.Params.customOpenapiURL }}
     {{- $urlOpenapi = .Site.Params.customOpenapiURL }}
   {{- else }}
     {{- $urlOpenapi = "js/swagger-ui/swagger-ui-bundle.js" | relURL }}