diff --git a/src/assets/styles/_common-variables.scss b/src/assets/styles/_common-variables.scss
index d4fd8c7..16167c0 100644
--- a/src/assets/styles/_common-variables.scss
+++ b/src/assets/styles/_common-variables.scss
@@ -1,4 +1,5 @@
 @use 'sass:meta';
+@use 'sass:map';
 
 body {
     --iqser-primary: lightblue;
@@ -45,10 +46,22 @@ body {
     --iqser-button-radius: 17px;
     --iqser-button-font-size: 13px;
     --iqser-button-height: 34px;
-    --iqser-font-family: Inter, sans-serif;
+    --iqser-font-family: "some placeholder value that should be overridden when configuring a theme";
+}
+
+$required-variables: "iqser-font-family" "iqser-primary";
+
+@mixin checkRequiredVariables($args, $theme) {
+    @each $var in $required-variables {
+        @if map.get(meta.keywords($args), $var) == null {
+            @error "Missing #{$var} in #{$theme} theme";
+        }
+    }
 }
 
 @mixin configureLight($args...) {
+    @include checkRequiredVariables($args, "light");
+
     body.light {
         @each $name, $value in meta.keywords($args) {
             --#{$name}: #{$value};
@@ -57,6 +70,8 @@ body {
 }
 
 @mixin configureDark($args...) {
+    @include checkRequiredVariables($args, "dark");
+
     body.dark {
         @each $name, $value in meta.keywords($args) {
             --#{$name}: #{$value};