diff --git a/src/router/routes/route_search_images.go b/src/router/routes/route_search_images.go
index 7aeb4715..b97e5744 100644
--- a/src/router/routes/route_search_images.go
+++ b/src/router/routes/route_search_images.go
@@ -121,7 +121,14 @@ func routeSearchImages(w http.ResponseWriter, r *http.Request, ver string, disab
 			Value:   fmt.Sprintf("%v", err),
 		})
 	}
-	catConf.DisableEngines(disabledEngines)
+
+	if catConf.ContainsDisabledEngines(disabledEngines) {
+		// User error.
+		return writeResponseJSON(w, http.StatusBadRequest, ErrorResponse{
+			Message: "category contains disabled engines",
+			Value:   "disabled engines",
+		})
+	}
 
 	// All of these have default values set and validated.
 	opts := options.Options{
diff --git a/src/router/routes/route_search_suggestions.go b/src/router/routes/route_search_suggestions.go
index 9dd43ba5..4f630568 100644
--- a/src/router/routes/route_search_suggestions.go
+++ b/src/router/routes/route_search_suggestions.go
@@ -78,7 +78,14 @@ func routeSearchSuggestions(w http.ResponseWriter, r *http.Request, ver string,
 			Value:   fmt.Sprintf("%v", err),
 		})
 	}
-	catConf.DisableEngines(disabledEngines)
+
+	if catConf.ContainsDisabledEngines(disabledEngines) {
+		// User error.
+		return writeResponseJSON(w, http.StatusBadRequest, ErrorResponse{
+			Message: "category contains disabled engines",
+			Value:   "disabled engines",
+		})
+	}
 
 	// All of these have default values set and validated.
 	opts := options.Options{
diff --git a/src/router/routes/route_search_web.go b/src/router/routes/route_search_web.go
index 3db29a7d..8d3c99b8 100644
--- a/src/router/routes/route_search_web.go
+++ b/src/router/routes/route_search_web.go
@@ -121,7 +121,14 @@ func routeSearchWeb(w http.ResponseWriter, r *http.Request, ver string, disabled
 			Value:   fmt.Sprintf("%v", err),
 		})
 	}
-	catConf.DisableEngines(disabledEngines)
+
+	if catConf.ContainsDisabledEngines(disabledEngines) {
+		// User error.
+		return writeResponseJSON(w, http.StatusBadRequest, ErrorResponse{
+			Message: "category contains disabled engines",
+			Value:   "disabled engines",
+		})
+	}
 
 	// All of these have default values set and validated.
 	opts := options.Options{
diff --git a/src/search/category/disable.go b/src/search/category/disable.go
deleted file mode 100644
index 9b8d58a2..00000000
--- a/src/search/category/disable.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package category
-
-import (
-	"slices"
-
-	"github.com/hearchco/agent/src/search/engines"
-)
-
-// Remove the specified engines from the Category.
-// Passed as pointer to modify the original.
-func (c *Category) DisableEngines(disabledEngines []engines.Name) {
-	c.Engines = slices.DeleteFunc(c.Engines, func(e engines.Name) bool {
-		return slices.Contains(disabledEngines, e)
-	})
-	c.RequiredEngines = slices.DeleteFunc(c.RequiredEngines, func(e engines.Name) bool {
-		return slices.Contains(disabledEngines, e)
-	})
-	c.RequiredByOriginEngines = slices.DeleteFunc(c.RequiredByOriginEngines, func(e engines.Name) bool {
-		return slices.Contains(disabledEngines, e)
-	})
-	c.PreferredEngines = slices.DeleteFunc(c.PreferredEngines, func(e engines.Name) bool {
-		return slices.Contains(disabledEngines, e)
-	})
-	c.PreferredByOriginEngines = slices.DeleteFunc(c.PreferredByOriginEngines, func(e engines.Name) bool {
-		return slices.Contains(disabledEngines, e)
-	})
-}
diff --git a/src/search/category/disabled.go b/src/search/category/disabled.go
new file mode 100644
index 00000000..da8733de
--- /dev/null
+++ b/src/search/category/disabled.go
@@ -0,0 +1,19 @@
+package category
+
+import (
+	"slices"
+
+	"github.com/hearchco/agent/src/search/engines"
+)
+
+// Returns true if the category contains any disabled engines.
+// Otherwise, returns false.
+func (c Category) ContainsDisabledEngines(disabledEngines []engines.Name) bool {
+	for _, eng := range disabledEngines {
+		if slices.Contains(c.Engines, eng) {
+			return true
+		}
+	}
+
+	return false
+}