diff --git a/CHANGELOG.md b/CHANGELOG.md
index aafa39682cdc4b70d121cc13fa837b10e86e3454..7416cb14af6d7a183260ee0a46d2860a640d1a31 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@ Note that since we don't clearly distinguish between a public and private interf
 
 ## [Unreleased]
 
+- Better guard against issue (black fringes) with bumpiness in impostors
+
 ## [v3.26.0] - 2022-12-04
 
 - Support for ``powerPreference`` webgl attribute. Add ``PluginConfig.General.PowerPreference`` and ``power-preference`` Viewer GET param.
diff --git a/src/mol-gl/shader/chunks/apply-light-color.glsl.ts b/src/mol-gl/shader/chunks/apply-light-color.glsl.ts
index bddbf634b013296a098601b85406adb334e5450e..ff2036d50cdc38547483552017dae5c90274bbcc 100644
--- a/src/mol-gl/shader/chunks/apply-light-color.glsl.ts
+++ b/src/mol-gl/shader/chunks/apply-light-color.glsl.ts
@@ -12,7 +12,7 @@ export const apply_light_color = `
     gl_FragColor = material;
 #else
     #ifdef bumpEnabled
-        if (uBumpFrequency > 0.0 && uBumpAmplitude > 0.0) {
+        if (uBumpFrequency > 0.0 && uBumpAmplitude > 0.0 && bumpiness > 0.0) {
             normal = perturbNormal(-vViewPosition, normal, fbm(vModelPosition * uBumpFrequency), (uBumpAmplitude * bumpiness) / uBumpFrequency);
         }
     #endif